It's pretty much the opposite of what you may think. I am asking here to verify or not if this is actually what the Buddha taught.
If for example a school says the Buddha predicted this person my only source of verifying that claim is to see where the Buddha predicted this thing, which I can do by either reading the entirety of the pali canon or ask those who have studied and practice the pali canon hence why i am asking here, Buddhists in a tradition that is about the pali canon, the actual Buddhas teachings.
This subject It is claimed by mahyanaist/vajrayana that Buddha predicted padmasambhavas arising, my only source of finding whether this claim is true or not is asking here.