Moving ISBNs when new edition is likely short term

[Antonomasia]

In this case it's for a small publisher series of classics, with the book/ISBN likely to be available in the main classics series cover after the series promotion, or possibly be available in parallel - but this also applies to some film tie-in editions.

In these cases is it still policy to move the ISBN to the new edition?

This is the ACE I was planning on creating: https://www.amazon.com/Villette-Moder...
in order to add it to a list for the publisher series Torchbearers

[rivka, Former Moderator]

Antonomasia wrote: "In these cases is it still policy to move the ISBN to the new edition?"

Yes.

[Antonomasia]

Does it get moved back later if the older cover becomes the main edition again?

[rivka, Former Moderator]

Also yes, although from what I've seen in a fair number of cases there is a slightly modified new cover, rather just moving back to the older one.