I can't really speak to any of the issues, but I post nevertheless.
When it comes to the first issue, the sad story is that although I am known as an SQL Server expert, I have never worked with SSIS. I have SSIS installed, but I don't have this login. I guess this is a login you get when you set up SSISDB (which I have not). I doubt that Microsoft would create the account with insufficient permissions, so if the account is missing required permissions, I'm inclined to suspect that someone locally has gone on a lockdown craze and removed one permission too many. Whether that could be more reasons involved, I can't say, as I have no knowledge about that update step. (There is another, more general, update script which is known to cause issues every now and then. But this script does not refer to ##MS_SSISServerCleanupJobLogin##.
For the second question, that is a question you would need to ask in a forum related to your virtualisation product. Although, without further knowledge, I am inclined to blame human intervention.