The wiki doesn't have any info about specific recent social media posts from Aiyuk, so I can't speak to that part. But on the bigger question of whether he'll be released — here's what the situation looks like:
The 49ers are almost certainly moving on. They've voided his contract guarantees and signed Mike Evans, signaling they've moved forward without him. As of late June, ESPN's Jeremy Fowler reported Aiyuk is "essentially untradeable right now" (from the Brandon Aiyuk page).
Here's the mechanics of it: Aiyuk is on the Reserve/Left Squad list and hasn't yet applied for NFL reinstatement — he needs to do that before the 49ers can release him. Once he's reinstated (expected to be automatic), he can report to camp and force a release by making the 49ers liable for $26M+ in injury compensation. On Underdog Fantasy Football, Josh & Hayden noted: "The longer they wait, the more likely the Commanders are going to say, 'You know what? I'm going to send you a seventh-round pick'" — which would help the 49ers financially .
Bottom line: Yes, a release (or a very cheap trade) looks probable. Aiyuk's preferred landing spot is Washington to reunite with Jayden Daniels, but the Falcons, Raiders, and Browns are also in the mix. If released, the wiki notes he may have to sign a veteran minimum deal rather than the $120M contract he once expected.