Something along these lines was in the beacon chain spec until about two months ago: see this version from October 3rd, second bullet point:
PoW Main chain clients will implement a method,
prioritize(block_hash, value). If the block is available and has been verified, this method sets its score to the given value, and recursively adjusts the scores of all descendants. This allows the PoS beacon chain’s finality gadget to also implicitly finalize PoW main chain blocks. Note that implementing this into the PoW client is a change to the PoW fork choice rule so is a sort of fork.
I can’t find the commit that removed it, but it’s presumably because it doesn’t belong in the beacon chain spec, rather an EIP somewhere.