Yeah, the excuse that the regular chapel is "too small" is total crap ... as that's often a "problem" for things like Confirmations at every chapel. So what they do is reserve a certain number of seats for confirmands and their families only, block those off, and then first come first serve for the rest. There's absolutely no need for it, or else you can just split them in half, where you do A-L one night, then M-Z the next night, more or less.
This is done 100% on purpose, but they often use various practical considerations as lies to justify it.
As someone else said, WORST case is that you can rent a large hall.
No, this was done precisely in order to get people more and more used to integration with the Conciliar Anti-Church.