Well, in the original Mirage comics April worked with Baxter Stockman in the tech/science industry.
Anyway, I re-read the section again
and now I do find it a bit suspect.
I still doubt it is meant to imply any previous continuity still exists but maybe as part of the experiments the turtles and Splinter have been mutated to humanoid form before, though never out in the open....? I've no idea. This is
Splinter calls the turtles all by their names but in the first issue it seemed implied that April gave them those names.