In Adventurers League, if a character played a couple of sessions of Season 7 contracting the Death Curse, and activating the modality "meat grinder", would that modality still be activated during sessions played subsequently but in adventures previous to Season 7?
In other words: does the Death Curse persist through different seasons played?
Best Answer
Yes. A character can become Death Cursed and carry the curse with them to other content.
A lot of this answer is going to cover the basics of the death curse, because understanding the whole thing is required to understand how it works in other content. All quotes are from the D&D Adventurers League ToA Player Primer v1.3.
Acquiring the Curse
The Death Curse is something a character has, not the content. The content listed above is where the curse is applied to the character, where it can become cursed. Once the character has the curse, they have it until shed (detailed below).
Activating Meat Grinder
At the instant the character picks up the Death Curse, they player can choose to toggle Meat Grinder Mode on or leave it off. That choice is permanent, as long as the character is Death Cursed.
Removing The Curse
Once a character has the Death Curse, there are a few ways out. Other than playing through Tomb of Annihilation (the "Defeating Acererak" option), the character can...
Nowhere does it say the character can't be used outside of curse-inflicting content. In fact, the only content restrictions are just the opposite. If the character waits it out, the character is barred from Season 7 T1 & T2 content.
That said, there are two ways "Waiting It Out" comes into effect:
Playing Other Content
There is no prohibition against playing other content.
In general, DDAL does not enforce timelining (as another answer implies). A character can be used in any content, in any order. The fact that some material was released before other material does not explicitly mean it takes place in the order it was released. While a timeline can be constructed, the DDAL administration has been reasonably careful to avoid explicitly laying one down for exactly this reason.
In fact, in many seasons (especially Season 5), to get the full story with a single character, you have to play the content out-of-order (relative to release) because T2 and T3 content came out before all the T1 content had been released for the season. To use a pop culture reference, for the most part, a DDAL character's personal timeline is a ball of wibbly, wobbly, timey wimey stuff.
The "hard" timelining only exists for the Season 7 T1 and T2 content and only as it relates to "Waiting It Out". The distinction of "circa Soulmonger" and "post Soulmonger" does not have any bearing on any other content, except explicitly listed above.
Anecdotal Supporting References
In face-to-face conversations with admins, we discussed whether visiting Barovia (Season 4 content) would allow a Death Cursed character to avoid the Soul Monger. I was told that the Soul Monger can't reach across planar boundaries. The conversation was quite specific on the fact that the character still has the Death Curse, and still wastes away if brought back from the dead, but the soul is not collected.