IMHO you should ask the new employer and act depending on their reply: they may appreciate the fact you are indeed so kind to avoid leaving before the release.

IMHO you should ask the new employer and act depending on their reply: they may appreciate the fact you are indeed so kind to avoid leaving before the release. However, if this will not be possible, to leave before the release makes sense to me, the problems after the release will go forward for weeks or months, one week more one week less is no difference IMHO. I would just say that I'm at their disposal for email questions if they find some of my code impenetrable, of course in a best-effort basis.