2 month old warm yeast cake?
My assumption would be it's probably nasty but I have no actual information on warm, liquid yeast cakes.
Might very well be just fine and it's just an unfounded assumption on my part.
I just assumed since all liquid yeasts always seem to be sold cold, shipped cold, stored cold.
No one ever talks about "warm" yeast storage. Except for dry yeasts and I keep those cold too.
As long as the keg/fermenter is sealed, I'm guessing there's not too much of a difference besides weight (CO2 vs fermented beer). I've not bled off the pressure from that keg, so what I may do is draw off some of the slurry and pitch it in a small batch (1-2 gallons) and see what happens on the next brew day.