Hello. I archived a couple of projects. When I try to use a name used by an archived project, it tells me that someone is already using that name. I would ask the support team to delete all my archived projects. Thanks.
Try unarchiving and give them some random name like part of a UUID or smth and then rearchiving
or if you want to say bye bye to the projects forever send an email to Glitch Support (mailto:firstname.lastname@example.org)