From the looks of it, he’s planning on abandoning since he’s now gone on to make a new game. Hate it when they do this same thing happened with polarity and the guy who made raptus.
One never knows, but he has not himself hinted at abandoning Estaria. It's fairly often the case that a first project is abandoned when the dev realizes that the early learning curve problems in essence makes the game hard to continue with. So, they abandon it, start a new game with what they've learned about the process or do a complete remake. More common than not I'd say. As for doing two games at once: also not unusual, some of my favorite devs do this to keep their interest up and avoid writer's block. But it is a bit dodgy because as soon as one game is more fun to develop than the other, that games tends to take precedence and most of the effort. Hopefully Royal is one of those who can juggle them both successfully, like Doc52, Neko-Chan, OnemanVN etc. Otherwise, yes, one of these games (or both) might be abandoned. Fingers crossed?