One thing I read quite early on, I think in Modern Railways, is that one TOC was quoted as saying something like "we've now realised we can operate a reliable service if we operate a more realistic frequency" or somesuch. The mind boggles as to why that never occurred to them before, but I hope, so far as is feasible, we don't see increases back to previous levels of frequency at known pinch points like Castlefield, but instead coupling those trains together to run longer trains on slightly lower frequencies that are appropriate to the infrastructure, allowing reliability and punctuality to return.
I think it's a genuine opportunity to deliberately not put some trains back again given that demand to fill them will take some time to return anyway. Not wholsales, just the last one or two trains that "fill up" busy peak railways.