At the moment there is an ATC service of sorts (though, as I understand it the actual services apart from the visual are provided by Waddington). Waddington is pretty close to Scampton at 5000ft and 300kts, though I doubt it will feel like that at 500 ft with no donk. If you were flying a Hawk T1 in that situation, would you expect to point towards Lincoln and try to get into Waddington or try and put down on the 9,000ft strip below? Answers on a postcard ... but the one thing that strikes me is that what is proposed is, on the face of it, less safe than what is there at the moment, which seems an odd position to take in the current climate.
I expect that the minister who announced the decision in 2018 was well and honestly briefed about the options for RAFAT (if not for either of the other units there!), but a significant airspace change such as the move of R313 would/will take years to get approved through the CAA, even assuming it were possible at all in the UK.
The Ministerial Announcement is available on line ... search Google for HLWS892 and you will see Earl Howe reference (and quote in full) the Syatement by Tobias Ellwood. I would post a link but the site won't let me.
There are 3 other aspects to the future of Scampton which are relevant.
1. Firstly, how suitable is the airfield for development? All bases are not created equal and I would be amazed if there was not a significant amount of remediation required. The RAF/MOD has no money to pay for this and any developer worth its salt will not want to invest without the prospect of significant returns, but this is only going to be possible if ...
2. ... there is significant demand for housing in the area - I do not think that is the case (more likely it's prime potato-growing land notwithstanding 1. above!).
and perhaps of less import,
3. The RAF is piling people into Waddington as fast as they will go. Use of the 'overflow' housing at Scampton is, I understand, likely to be necessary for some years. That said, the housing there is not owned by the MOD (thanks to Mr Portillo), and let's not forget that the announcement on Scampton was made, ostensibly, based on the DIO requirement to 'Make Better Use of Defence Estates'; given all the problems which have come to light since the announcement, I am not sure quite how this is being achieved.
Time will tell.