While there probably are some places in the UK that serve squirrel and some some sort of hunt/game menu, I've never seen it, let alone eaten it, myself (brit here. There is absolutely no shortage of any other meat.
If they're going to do propaganda, they could at least make it somewhat believable. I mean, just last month we had Theresa Coffey's 'let them eat turnips' moment so why they went with squirrels and not turnips I don't know.
Definitely doesn't sound appetizing to me but I had a friend once who ate squirrel and said it was nice
It's apparently a proposal from an animal rights group to encourage restaurants to serve grey squirrels on the menu to encourage hunting them down because they're an invasive species which has decimated the red squirrel population.
But yeah, Russia dumb as shit.