An engine change is coming, huh? Hopefully it's not Unity or Unreal because if it's a full on 3D game, I probably won't be able to play this anymore (thanks to my weak ass laptop).
As crow said: "In addition to working on the next update, I’ve been testing new systems that support all our platforms (PC, Android…) while also opening the doors we need to go further. And I found what I needed." I doubt if it's will be heavy since it's gonna be playable on Android