Okay so First Episode Review is a go:
The first scene with Yhwach's Origin is both something we knew and surprisingly new at points(So Yhwach was born naturally, not just appeared in the wild like we first thought... but he literally absorbed his mother after that) and we see a really cool shot of hundreds of hands touching baby Yhwach just to get absorbed and fuel him which I gotta say is actually very effective.
The OP is... actually pretty nice. The Song is catchy but ok and while the Opening itself is weird(As it's not a typical action OP), it still parallels everything that will happen in the arc.
While the basics are the same(There are no fully revamped scenes), they add in alot of extra context Kubo didn't do before(For instance, we barely get anything from the type of training Ichigo, Rukia, Renji and Byakuya go through, it's explicitly stated by Ichibei that he's still not strong enough to tango with Yhwach and he "has to go beyond the level of a Soul Reaper" to do so, we get a scene that has Shunsui actually question Ichibei's motivations for taking Ichigo, showing that while he will do the fucked up thing, he's not a fan of doing it to Ichigo at all). It only sucks we still get nothing with Chad and Orihime though outside of their bare scenes of them stating they are training and after that.
While we do get a bit more into the context of the Schatten Briech, it's still not much either which is also a minus. The effect of it overriding the Soul Society is A+ though.
Ultimately, I will give the episode 7/10. It's obviously not action and the calm before the storm and while they did add extra context here and there, I wish they would show more and revamp some scenes entirely(Show Chad and Orihime train or even fight off some of the remaining Quincy in Heuco Muendo, show an extra scene of the Stern Ritter chillin' and being human like releasing that Omake of Bambietta trying to ask Haschwalth for a pay raise in disguise of Holiday money, actually state why Ishida survived Aushwalen(I think this may be stated later though considering I know people have asked Kubo questions like that and he basically deferred to the Anime). But it's not bad overall for what it's setup to be and everything else was still fine.