When a version has received its last update (before a new version is released) the coding should be corrected so that the program no longer checks for updates since there won’t be any.
But that does not answer why the NIK plugins or the dop.cor whatever tries to connect to the Internet every time. The first time you use the program maybe, but not after that.
No its not useless concerning checking for updates at startup, which it will not do when checked. Than you have to do it manually. Rest see above. Film Pack und Viewpoint you can also uncheck autoupdate. But no idea if it connects like PL for license check. Use it almost not at all as a standalone.
Nik collection also seems not to connect on a regular basic like PL. (All Mac related)