What OP talks about is only syntactic transformation which leaves semantics unchanged and probably "know" nothing about semantics of the code being translated, or might be being aware of a few standard ideoms, the same way macro transforms in Lisps do.
Transforming from one language to another is also old idea, some Scheme systems transforms (compiles) into C first.
In both cases the transformations themselves must be defined precisely by a programmer in advance. The idea that a program could transform semantics of another program is still a fantasy.) Even for Haskell.
I know, and I agree that having one program transform the semantics of another gets into the realm of fantasy.
I don't want to eliminate the role of human developers from the process. Instead, I want to provide tools that the human developer who understands these semantics can use to express the desired transformations, and tools that will help carry out those transformations across a huge codebase. Tools that "magnify" the efforts of the human who has the deep understanding of the before and after semantics.
Transforming from one language to another is also old idea, some Scheme systems transforms (compiles) into C first.
In both cases the transformations themselves must be defined precisely by a programmer in advance. The idea that a program could transform semantics of another program is still a fantasy.) Even for Haskell.