Well I'm facebook "friends" with Simon, and he didn't sound too encouraging about future shows, but it was just cryptic enough for me to still have hope. Someone asked if there were plans to do non festival dates, possibly in the US? And he wrote, only the dates published. And it sounded like he was going to be playing with them. Whether he meant he would only play the festivals with them, is anyone's guess. :/
I don't think we know anything, other than they're playing some festival dates in 2019. Could be just a way to make some money to fund the remaining to-be-remastered reissues and future solo projects. Although Tim did say once he had no interest in reforming just to play the hits, so we may get something new. Here endeth my speculation.