On the subject of Joey being fired, (not speaking about Chris as there was clearly some shady shit going down to which we may never fully get the truth) but back to Joey, this came out a few years after he was gone and people always seem to either not know or glad over it.
The real reason Joey was replaced
As you can see for whatever reason at the time neither the rest of the band nor Joey disclosed this. Could that have waited for him to get better? Maybe, but some people with TM don’t get better the way he did.
In closing, remember this despite it not being disclosed originally, it wasn’t as if the band said “Fuck you Joey you’re out” there was a legitimate medical issue that led to him leaving.