People already told it, but you seem to not understand it.
Your internal RAM is split in several partitions (system, data, cache, ...), one of them, the System, contains the Android OS and system apps, like telephone, google maps, browser, gallery, ... and pre-installed bloatware depending on your operator and the manufacturer, like Facebook, WeChat, shopping apps, ...
You and apps don't have write access to this system partition. So you're unable to change system files, but also are unable to remove apps from the system partition.
If you update one of those system apps, the update won't be installed on the system partition but on the data partition to which you have write permission. Thus you also can only remove the updates later.
If you don't like one app placed on the system partition, then you can freeze/deactivate it. It won't run any longer, and won't gather any user informations, it's impossible! It's just as if you removed it (except that the apk file is still on the system partition, but it's useless)
The alternative is to gain root access, then you can write to the system partition and remove the apk.
But because you have difficulties to understand the very basics of Android you should avoid rooting because you will understand this process and the consequences even less.
Your link about 'Study shows major generational divide on online privacy attitudes' has nothing to do with this thread or Android at all. It's about the beahviour of people using the internet and sharing their personal informations in general.
The link on engadget, again, has nothing to do with this thread. It's about updating an app outside the play store which got installed via the Play Store. Thus, in the past, you could upload a safe app to the play store and auto-update to a malicious app later. Now this won't be allowed any longer. It's probably also not directed directly against Facebook, because, as far as I read, did Facebook use this feature to offer beta versions to interested users and not to circumvent the Play Store. But again, this article has absolutely nothing to do with the problem you have described in this thread.