First, a picture for reference:
My question is: if I were to take the neutral wire coming from the light out of the wire nut bundle and instead put it into the second hole next to B, would it be electrically the same? Or is there something I'm missing here.
For context, there's a second switch in the same gang box. The hot line wire comes into this switch, then out of the second hole into the line terminal of Light 2. Light 1's load hot wire comes into the load terminal. Light 1's load neutral wire plugs into the neutral terminal. The second hole on the neutral terminal goes to a wire nut where the power line's neutral, as well as the neutral for Light 2 are connected (possibly in the same way, I'm not sure. I'd have to pull them out again to be sure).
Best Answer
The two push-in terminals in those holes are directly connected, electrically continuous, or equipotential for a really high priced term. Connecting the two neutrals to them would work just like the pigtail connection illustrated would. There are a number of reasons NOT to use them though.
Number one, the push in connections on receptacles and switches generally don't make a good connection, even though they are approved, legal, etc., they often cause problems, some minor, some major. I never use them. Ever. (Now the push in connectors are not to be confused with the backwired connections that operate with a screw clamp - those are fine.)
But you could use the screw terminals to achieve the same end; the two neutral screw terminals and push in terminals are all connected. This would again be legal and a good reliable connection.
If this circuit is a multi-wire branch circuit that shares the neutral with two 15A or 20A circuits, there is a code issue using the screw terminals: there's a rule that devices on those circuits must be wired in a manner such that removing the device does not open the neutral.
This may be why the illustration is as it is: pigtailing the neutral may not be required, but it never hurts.