My work isn't what I would call highly professional in terms of infra, but for us the old URL from our Jira move is dead and gone (including the parent domain) but the ticket references work in the new instance (redirecting to a new project name also). I think you just have to pick your poison, nothing's going to work all the time without small amounts of effort from IT.

Definitely - we recently moved issue tracking to another system after 15+ years and found there were too many links to abandon, so we run a service that just redirects old URLs.