Do old packets ever go away on the Internet? How many DNS packets still wander towards SRI-NIC.ARPA's old root server at 18.104.22.168?
At some point, regardless of what the lawyers say, you've got to make your
own decision and move on. Things change on the Internet, if you don't
maintain your systems they will become obsolete. Conversely, no matter
how many ways, how many times you try to inform people about changes
someone will miss it, ignore it, misunderstand it, etc. And someone
may even sue you over it.