I do not know all of the details of how ChainLink's nodes and oracles work (hence why I am on here) but I did a little research on my own. According to a Gemini blog post by Cryptopedia, chainlink uses an aggregating contract so that
if five nodes deliver one answer from a weather sensor and two other nodes deliver a different answer, the Chainlink Aggregating Contract will know that those two nodes are faulty (or dishonest) and discard their answers. In this manner, Chainlink nodes can validate data from a single source.
So it seems ChainLink's oracles are based on a majority rule type system. So, if an oracle holds a substantial amount of LINK and is reputable enough, could it influence/control/change the number generated in a specific call for ChainLink's VRF? Would it be considered a 51% attack?
I understand it usually would not be worth it because of all the LINK they'd have to have staked would be devalued. (I think?) However, if the number was to be generated for a lottery and the lottery was a few million dollars in ETH (or let's just say "worth" manipulating the number), could it be possible?