That only matters if expression of the original project really does end up in the rewrite, doesn't it? This can be checked for (by the team with access to the code) and it's also quite unlikely at least. It's not trivial at all to have an LLM replicate their training verbatim: even when feasible (the Harry Potter case, a work that's going to be massively overweighted in training due to its popularity) it takes very specific prompting and hinting.