MC had theoretically decided who he wanted to be with in the chapter before, and apart from Maya and Josy to whom it had not been possible to communicate his decision (but who were the only ones with whom there was already an official relationship at least between them), with the others everything was already defined.
besides M+J there were two other situations, optional, pending: the triangle with Bella and Jill, which we can't say in any way solved, so towards them Mc evidently doesn't know who to be with, and the triangle with Sage and Jade, also not solved at all and postponed.
then of course relationships consolidate, develop, but the arc of the big decision was already concluded (or never..)
then that Mc now knows who he is... I don't know... I don't think so
we see the consequences from chapter to chapter, of course we saw them in 9, but we'll see them also in 10, in 11 ....
chapter 5, which isn't one of my favourites anyway, closed the hells week arc for real with Derek and MC becoming DIks for all intents and purposes, and also set the stakes for the whole second season for M+J and consequently for the other LIs, as well as giving the premises for the main narrative cue of the chapter (Tybalt's blackmail)