I doubt he's celebrating the deaths or the rise in case numbers. I think he, and a lot more Mancs, were left wondering just what the criteria was that meant London didn't have a Tier3 worthy problem two weeks ago. Manchester was basically operating under 2/3 rules from late July and got very little financial help - when Andy Burnham etc complained that punishing a region for being poor, having overcrowded housing etc, wouldn't fix anything, and the lack of support was making it poorer.
From a Manc perspective nothing changed until London got caught up in the restrictions and suddenly Burnham's unreasonable demands were easily met for London and the south, but were not backdated to deal with the same problems in areas who'd been coping for longer.
The question of criteria made it worse - when Manchester went into local measures it had less cases/100k than most Tier1 areas do now. When the post-national lockdown tiers were announced Manchester's rates were falling fast and London's were rising and they weren't that far apart even in raw numbers.
On an emotional level there's a big slice of schadenfreude underway. On a practical level though - there's a real sense that actually the government does bugger all to help people or businesses until it effects the capital, at which point they notice that there might be a need to do something. In other words, there is something in it for other areas in trouble. London going into Tier 3 will do a lot more for the other local support packages than Newcastle did.