User blog comment:Xilinoc/Ch. 581 - THE HERO 2/@comment-2048489-20140522040512

Don't know about you guys but I feel like Ichigo showed up at a reasonably good time plot wise. The breather that Kubo gave everyone from his presence was just about right, and it wasn't like people were totally helpless without him either; I'd say the Shinigami are actually doing pretty well considering that they are essentially neck-deep in enemy territory right now. It's very clear that they're at a disadvantage, but despite this they've had a few small victories of their own. Enough that Ichigo returning doesn't feel quite as much like a Deus Ex Machina situation to completely turn things around so much as "reinforcements" or "fresh troops", you know what I mean? Him returning feels more like hope is returning rather than "victory is assured".

Basic summary: his reappearance was well-timed on Kubo's part.