I’m not a lawyer but, I know when you file for a patent you can do that in just one country or internationally (which is significantly more expensive). Skimming through the Wikipedia article it seems to be talking about that, but first you need to have filed for the patent internationally and not in just one country.
From what I’ve read about this topic, it sounds like this is a patent active in Japan only.
Sure, just like other brick and mortar stores can refuse to give you backups of a DVD you own.
As long as the installer works offline this is just as good. It’s up to you to store it in whichever format you prefer so that you don’t lose it - hard drive, thumb drive, DVD…
If you nuke your computers hard drive with the installers of your games, or you step on your blu rays with games and break them, then you lose access to them. As it’s always been, no matter the format?