A Glyph wards an area or an object. While the trigger can be refined to be conditionally dependent on (almost) anything you want it still probably necessarily needs to interact with the area or object you've warded:
You decide what triggers the glyph when you cast the spell. For glyphs inscribed on a surface, the most typical triggers include touching or standing on the glyph, removing another object covering the glyph, approaching within a certain distance of the glyph, or manipulating the object on which the glyph is inscribed. For glyphs inscribed within an object, the most common triggers include opening that object, approaching within a certain distance of the object, or seeing or reading the glyph. Once a glyph is triggered, this spell ends.
The above quote, preceeding the section on refining the trigger, does not indicate that the trigger can be anything but rather that it can be lots of things and also lists several things it definitely can be. If you go outside that list for the basic trigger, you need to confirm with your GM that the new trigger is possible. Unlike the open-ended section on refining triggers, it is not the case that the basic trigger can accomplish what you want.
Furthermore, there is historical precedence for it not doing so; Glyph of Warding in earlier editions of the game, while always very open ended, specified some version of the following clause (taken from AD&D 2.0):
A Glyph of Warding is a powerful inscription magically drawn to prevent unauthorized or hostile creatures from passing, entering, or opening.
which indicates the general scope of potential triggers-- they must in some way relate to the warded object or area. Refinement, however, is not nearly so limited.
This means the following death triggers are possible:
This Glyph, placed above a doorframe, triggers upon any creature entering if Aroden is dead.
This Glyph, placed upon the floor of the room, triggers if Aroden is killed while inside the warded area.
This Glyph, placed upon the surface of Aroden's back, triggers upon his death
But the following triggers probably don't work:
This Glyph, placed upon the wall of the study, triggers upon Aroden's death
This permanent Glyph, placed upon the ceiling of the sitting room, creates a bright flash of light each time a creature dies.
In conclusion it's not proximity but interaction that matters, but proximity is usually a prerequisite of interaction. Non-local parts to trigger's refinement are fine, but the trigger itself (very probably) has to involve the warded object or area in some way.
Addendum for the specific purpose of dead-man-switching a WMD:
You can do this with the spell, and it is very appropriate. What you want is a glyph on each weapon that triggers "When a person not bearing the Royal Seal attempts to move, activate, or dispel the object, or if the object is moved, activated, or subjected to dispelling forces in any way and I am dead", and then you just tell the kingdom about the first part. You can't make the devices trigger upon your death but you can make them (and any other devices you feel so inclined to affect) work fine until you die and then turn upon their masters if they are ever used past that point. Basically, you are creating a cursed item whose curse's activation is delayed until your death.
This kind of warding, though, is still somewhat risky, since the glyph can be dispelled if the dispelling is done carefully, and then replaced with you none the wiser.
You could also ward yourself with a (surface, and thus mobile) Glyph that triggers when someone approaches or strikes the surface with the intent to kill you, and have that Glyph somehow remotely trigger the deadman operation via your choice of long-range communication spells and recievers, but you should be aware such a measure can be triggered against your wishes by a clever opponent of your home nation, or bypassed via clever assassination methods (e.g. poison for the specific wording I mentioned)
Basically, this does almost exactly what you want it to for your linked answer, but is a lot less infallible than you might have first thought.
You scribe the circle and runes when creating the glyph.
Glyph of warding:
Spell Glyph. You can store a prepared spell of
3rd level or lower in the glyph by casting it as part
of creating the glyph.
...
At Higher Levels. ... If you create a spell glyph, you can store any spell of up to the same level as the slot you use for the glyph of warding.
Teleportation circle:
As you cast the spell, you draw a 10-foot-diameter circle on the ground inscribed with sigils
(PHB, p. 246 and 282, emphases mine).
To put the teleportation circle in the spell glyph, you have to cast it, including drawing the circle and sigils. You can't have them drawn when the glyph is triggered.
Best Answer
The creature that triggers the glyph will be teleported to a place the caster chose upon casting
Your second option is the correct one.
Misty step has a range of self, which means it only targets a single creature. As such it is qualified to be cast and put into a spell glyph.
As for what happens after it triggers, glyph of warding says:
You cast the spell fully when you put the spell in the glyph which means you also need to choose the parameters of the spell, just as if you were casting it normally.1
Note that the creature who triggers the glyph is not considered to be the caster of the spell, it is considered to be the target of the spell. Essentially, the glyph casts the spell by proxy. Normally this means that the creature would have no input on how the spell works it would just receive its effects. The ambiguity here is that misty step has a range of self which means that normally, the only person who can be targeted by the spell is the caster.
In this case, however, glyph of warding overrides that and makes them the target of the spell even though they are not the caster. And, because the spell has already been fully cast, there is nothing else for them to choose.
Thus, they are teleported according to the conditions set on the original casting of the spell/glyph.
1 - This means you also technically would choose a target/area for spells in general when you cast them. However, after triggering, this is the one parameter that glyph of warding overrides.