Much more experienced and expensive players have revealed a transfer on social media before the clubs have announced it. He's not the first and won't be the last.
Maybe it's not seen as a problem.
Perhaps it's seen as a gamble worth taking as, yes, chances are it'll just be development football for a while but then there is the chance to breakthrough at a team chasing promotion to, or trying to stay in, the prem, having had time to get a more rounded...
One of the biggest complaints about Lua Lua is that he sometimes is more effective as a sub than a starter. If this guy is essentially KLL2 we can start KLL and bring KLL2 on to freshen it up