Usually the point of "software update frameworks" is to make the app phone home and check if there is an update isn't it?

I mean you can have an option to not make it check for updates if you want to provide a privacy option for people, but that just makes it a manual click-to-check-for-updates. Most people would probably leave the "check for updates on start" checked.

Can't see how that's a difference based on what OS you are on? I use Squirrel/Velopack (the equivalent for Windows I guess) and the usual way of managing updates is to have an update check at startup, or an interval (e.g. every hour).