It might make sense if you subscribe to the idea of conformal cyclic cosmology. Where the big bang marks the transition between eons
Once everything in the old universe has been reduced to photons, and all the black holes have evaporated, the universe loses its sense of scale, and resumes operation as a universe the size of a grapefruit (or the size of the earth - I don't think it matters).
I don't know how Penfold thinks this resizing is supposed to happen, for example whether it's instantaneous or a slow process.
I'd love to have a few beers with Penfold; a lot of what he thinks about isn't maths or cosmology, and isn't all fit for publication, but I imagine it must be very interesting.
One could arguably say it's when there are no fermions from the previous one anymore, but that can be contested.