Interesting question: does a black hole initially formed of a cubic lightyear of cheese retain its calorific content?

I'm going to say no, because the black hole will be more dense than a neutron star, where chemical energy (and, more generally, chemistry) can't exist because protons and electrons fuse into neutrons.

The energy still exists, presumably, but claiming that's relevant would be like claiming a cheese at the top of a hill (potentially about to be rolled) has more calories.

In a previous life, I spent a lot of time backpacking, and half-jokingly made a point of stopping to eat/drink before bigger climbs. More fuel in the furnace, and less to haul up in the pack.

In that context, the cheese at the top of the hill really does have more calories or value or something along those lines.