Geez, I feel like the default behavior for that move should be to refund the content that is removed, does the content become available if you move back?

Yes they do.

I have a little "dance" I have to do to change my store back to the UK (I'm British) and you need a valid british credit/debit card and address to switch stores to the UK store...

I live in Sweden now and I got a bit bent out of shape when I moved and discovered this was the case.

Btw, buying things doesn't mean they won't remove it: https://blog.dijit.sh/importance-of-self-hosted-backups/