It's too early to say. The devs have said they considered extending KSP1 but chose to rebuild the game from scratch to enable things that never would have been

It's too early to say. The devs have said they considered extending KSP1 but chose to rebuild the game from scratch to enable things that never would have been possible in KSP1. Namely, acceleration during time warp. So I think it's fair to expect that KSP2 today will be lower on the y-axis of features than KSP1, but has a greater slope and will pass it and keep going at some time in the future. It's anyone's guess when that time in the future will be