

Possibly, but I don’t see Google doing that either. It’s not about where the app comes from really. The thing they are going to restrict is the developer. A developer can not have their app installed on a certified phone, regardless of where the user got the app, if the developer is not registered.
So, since there are no regulations to allow a user to install apps from any chosen developer, only from any chosen app store, there likely will be no regulatory recourse like Apple is facing as mentioned by the OP.
Again, adverse effects doesn’t mean death, the fact that the description you posed has that last sentence is the alarmist thing and only applies to certain drugs, of course.
The difference in absorption rates between oral and rectal administration can be as much as double or triple or more in some cases. For example I remember reading a study from the 70s or 80s on methylprednisolone. The absorption rate orally was about 90%, but rectally was only around 35% likely due to bacteria in the rectum decomposing the drug before it could make it into the blood.
So, over the long term the difference in dose could have a significant impact on health. Getting 3 times more or less of any drug, even something relatively safe, will likely mean “adverse effects”. With estradiol this could mean greatly increased side effects for overdose like nipple soreness or mood swings, or greatly decreased effect for underdose meaning testosterone takes over again and hair loss and body hair growth restart. These are “adverse effects”, but are not likely to be deadly, but still considered overdose/underdose.