Well one difference might be that you are not in the SIAC yet and WSSU was immediately let back in. Or it could be the fact the that WSSU is in the CIAA and not the SIAC (where fcuked up stuff always happens) But its no big deal. But umm yeah but no, we are officially in the SIAC https://thesiac.com. It's really a THING. It's not provisional, delayed, or conditional. Kinda like what you said "immediate."
Now what we can't do is "immediately" compete for a championship given the NCAA sanctions.
You said you are not provisional but your link said this.
"Savannah State also advanced to provisional year two
of the two-year reclassification process from Division I. The Membership Committee noted significant concerns related to Savannah State’s compliance program, its recent major infractions case and probationary status in Division I, and its overall readiness to be an active
Division II member. "
This quote from your link sounds like you are provisional and not a full member (i.e. you are not considered DII yet), which is why you do not qualify for any championships. My understanding is that only full DII members qualify for championships. Ergo, you are not an official member of the SIAC until you pass the provisional stage and qualify as a DII member. Simply put you can't officially be in a DII conference until you qualify as a DII member. What else you got?