In pure basketball terms, this gets a "meh" from me. This is a guy who played almost no meaningful minutes in March over his four years. He seems like a nice guy, but a limited basketball player who just never really developed. I wish him the best and hope he finds playing time somewhere.
The only thing remotely surprising here is the timing. I don't know why he didn't just announce before the deadline. I can't imagine anyone led him to believe that he was going to start next season. Still, I suppose things got more real lately with AJ Green coming for a visit. Joey would certainly be behind Green/Keels in the rotation, and might have to battle with Catchings and Schutt for bench minutes.
I have to say that the Senior Night thing is a total non-issue for me. It was rumored at the time - and reported by Matt Norlander - that Joey was coming back for a 5th season. Joey later even announced that he was returning. It would be silly to do a Senior Night ceremony for someone who wasn't playing his last game in Cameron (for contrast, compare this to Goldwire last year, who went through Senior Night and then later went into the Transfer Portal). It seems obvious to me that Joey planned on coming back, then changed his mind. It happens.