'Most physicists' - care to cite that?
The majority expectation on current information is heat death, that the universe will simply wind down, exhaust it's entropy, until no more change is possible. Only in the most abstract sense will time cease though. The other major scenario, depending on how dark matter and dark energy work out, is a 'big rip', where galaxies continue to accelerate apart from each other, becoming seperated by their own event horizons. This experience considerably slower heat deaths.
But the nature of time is an open question. Given that general relativity, the theory of gravity and time, needs to be reconciled with quantum field theory, it's very likely that will shift our understanding of space-time, probably to seeing it as emergent from a wider event space.
Scientists don't do proofs. They do evidence. And the jury is very much out.