Interestingly enough though removing preinstalled apps with `adb pm uninstall --user 0` (0, perhaps unexpectedly, being the main user, not root) does have a similar effect to disabling it, except it saves space permanently and only leaves the original APK in case of factory resets (not only this, but this works on what cannot be disabled otherwise, e.g. Google Play on some devices).

Just a side note that rooting may not be necessary. (even if I would love me a true Linux phone :)