Martin has made no guarantee of compatibility or even to supply a Scalafix app. The fact you can do this relatively easily today is just a consequence of Dotty being very young. As it evolves and becomes more complex, there is no guarantee that a translation from Scala to Dotty will even be possible to achieve automatically.
Re:Dotty 0.2.0-RC1
by virtualwhys on Wednesday July 12, 2017 @02:33PM
(#14755215)
> Martin has made no guarantee of compatibility or even to supply a Scalafix app
The entire point of scalafix[1](developed by the Scala Center) is to bridge the gap between Scala 2.x and Scala 3/Dotty. Martin talks about it in every Dotty presentation.
The above has been said repeatedly by Martin Odersky (creator of Scala) and the folks on the Scala compiler team in talks and discussions.