I had recently installed Grapheneos on my pixel, with a goal is determining what was responsible for all the senseless Google domains that a pixel normally contacts.
To my surprise disabling Network for the Google Services Framework and Play Services killed all of the nonsense. The only downside was that GSF has the push mechanism in it also, that many apps use for push notifications.
If only there were an alternate for push notifications that all apps would use.
Anyway, Grapheneos runs way cooler than Google's Malware version.
Um, if you're security minded, you're already staying far away from Authy, so I'm not really sure what the article's focus is.
That said, I'm using 2fa all day long on Grapheneos. No issue. And prior to Grapheneos, I ran rooted and had been using Authy with no issue, so this kind of sounds like an advertisement piece for Authy.