There's actually a reduction in EMR services at Doncaster, as the early Leeds-London via Doncaster service (1C15) doesn't run any more. In fairness, it's more of an ECS that happens to run in passenger service (as far as Sheffield, that is).
As for the Joint Line services at Doncaster, they remain as pointlessly timed as ever. Taking the southbound departures, 09:47, 12:47, 14:54, 18:47 and 20:49, I think just about the only praise that can be given is that the services all run through to Peterborough, and that they're approximately all xx47 departures.
There's no consistency whatsoever to the spacing of departures (three hour gap, then two hours, then four hours, then two?!), there are no arrivals or departures until well past 9am, and there's a massive gap around the evening "peak". So it's completely useless for any kind of conventional 9-5 commute.
I'm sure there are perfectly good operational and other reasons why all this is the case, but you have to wonder whether it's even worth spending the resources to serve Doncaster on a 5tpd basis if it's going to be such a useless service.
Arguably they'd be better off running the minimum sustainable level of service (so as to avoid loss of route knowledge), using the freed-up crews and units for better purposes (e.g. strengthening or peak extras) until such time as they can rustle up an hourly service.