Should he/they resign? Yes I think so. Although that should have happened before.
Will they? Almost certainly not. The timing helps in that respect, with parliament not sitting etc - no doubt thats one for conspiracy theorists, not without reason if I'm honest.
Do I care? Not enormously. Partly due to the nature of it, and partly because in practice i don't think the parties/gatherings were a risk to public health and this was the epicentre of decision making. Also, I don't mind a fixed penalty notice. It's not the crime of the century, although I fully appreciate the people involved amplify any indiscretion. For me though, Covid, lockdowns, WFH and the rest have decimated our society and I think it all should have been challenged a little more.
It's unbelievably hypocritical though, and one of the most clear cut examples of 'one rule for them and one rule for the rest of us' you will ever come across.
He should resign, or offer the mother of apologies, including a strong apology for the extent of the lockdown.