In the address form for a request for global rename through Special:GlobalRenameRequest, there is a check box to suppress redirects from being created after the rename. The box does not work, redirects are not created no matter what.
This should be fixed post SUL finalization.
Right now, when renaming people for SUL finalization, I think leaving redirects is a very bad thing. If User:Foo is renamed to User:Bar so that the global User:Foo can have their account, then that userpage/talk page that is being replaced with a redirect actually belongs to the global account owner who may have a global user page that should be displayed.
It's quite the quandry. Thoughts?
Redirects are only suppressed if we're doing a local account rename --> global account, the UI should be more consistent about that. But the rationale is that the local account now belongs to a different user (whoever owns the global).
Okay, so once SUL finalization is complete this bug will be deprecated since we will no longer be moving local, unattached accounts to global ones, which is where this shows up.
The same happens with forced renames, e.g. https://it.wikinews.org/wiki/Utente:Nemo
This userpage also has an incoming link from main namespace and making it a 404 is clearly a bad thing. On the other hand, the deletion box at the top serves as a pseudo-redirect for attentive humans and creating redirects manually where appropriate is cheap.
I think the strongest argument for not creating redirects by default is that deleting a redirect requires a sysop, which many wikis don't even have.