concurrent work (https://arxiv.org/ftp/arxiv/papers/2401/2401.04349.pdf) has shown website fingerprinting, recognizing something like the static login page of youtube/google/facebook etc is very much doable.
that said, I don't expect to see any of these attacks in the wild. they're primarily demonstrations of the technique and to show that the channel is there
as is often the case with side-channel attacks, a serious attacker would much more likely go for un-/recently patched traditional vulnerabilities