Product should have nothing to do with refactors on the systems.

Let's assume the reasons to refactor are:

1. Reduce unnecessary complexity, and

2. Reduce the gap between the code architecture and our current understanding of the domain.

Sure, you could refactor and preserve 100% of existing system behaviour, but:

- why not take the opportunity to discover the remove features that are annoying to maintain, but that the ops folks can live without (with some process change)?

- for #2, product folks can be helpful