All their apps are available on F-Droid, unless you want to build them yourself: https://search.f-droid.org/?q=secuso&lang=en

What privacy issue do you see/know involved with GitHub?

Microsoft aren't exactly known for privacy, given how much data they collect continuously from Windows users (e.g. details on every application you launch, hard-drive wide program sweeps, etc). Also with Github specifically they used everyone's code to fuel their machine learning product without asking permission.

That GitHub may be related to non privacy-friendly actors does not make software hosted on GitHub lose any privacy-friendly quality.

Was it meant to be a "don't deal with those guys" stance? Practically, that would further force us as nomads.