We had that some time ago with a service account for a specific system where individual personal accounts weren’t (yet) feasible. The credentials were supposed to be treated with confidence and not shared without the admins’ approval. Yeah, you can guess how that went.
When the time came to migrate access to the system to a different solution using personal accounts, it was announced that the service account password would be changed and henceforth kept under strict control by the sysadmin, who would remotely enter it where it was needed but never hand it out in clear text. That announcement was sent to all the authorised credential holders with the instruction to pass it on if anyone else had been given access, and repeated shortly before the change.
The change was even delayed for some sensitive reasons, but eventually went through. Naturally, everyone was prepared, had gone through the steps to request the new access and all was well. Nobody called to complain about things breaking, no error tickets were submitted to entirely unrelated units that had to dig around to find out who was actually responsible, and all lived happily ever after. In particular, the writer of this post was blissfully left alone and not involuntarily crowned the main point of contact by any upset users passing their name on to other people the writer had never even seen the name of.
Our system wasn’t quite as critical, thankfully, but the app owners failing to respond to “Hey, by the way, your service account for your data base is gonna be closed” is just gross negligence. My condolences that you had to take the brunt of their scrambling to cover their asses.
For all the complaints I may have about certain processes and keeping certain stakeholders in the loop about changing the SQL Views they depend on, at least I acknowledge that plenty of people did heed the announcement and make the switch. It’s just that the “Oops, that mail must have drowned in my pile of IDGAF what our sysadmins are writing about again. Can’t you just give me the new password again, pretty please?” are far more visible.