"I am staying because City can't pay may release clause and my lawyers have fucked me over! Visca el Barca i visca Catalunya!"
PS. Can Luise please stay?
Yeah, that's exactly how I imagine this will end. Basically his lawyers got it all wrong and they will admit this in the public statement.
They don't think their case is strong enough to win in court so they'll just back off now. In addition Messi will be seen as a victim on media because La Liga + Barto didn't want to offload him.
Actually this time now is the perfect time to announce his stay. He will make the club and La Liga look reaaaaly bad and he will end up as the "good" guy.