Not sure what you mean SafetyNet being triggered when uninstalling apps? Though I don't know what OEMs are doing on their devices, Pixel doesn't come with Facebook pre-installed and YouTube is pre-installed on the system image so you can't really uninstall it.
Maybe this is some specific OEM doing something odd on their device? Which device do you see it on? What is the experience caused by SafetyNet being triggered?
@hackbod
This wasn't direct or serious.
What I mean is unlocking the capability to even uninstall these apps first, unlocking bootloader and deleting the apps from system partition.