The list of summits in the UK is based on the Marilyns as described by the RHB Group. These guys are only interested in getting to the summit.
For SOTA we take that list and add the idea of AZ (Activation Zone) because that makes it possible to setup a station "at the summit" that is less of an inconvenience to other people and makes SOTA practical.
SOTA adds the rule that you cannot go to somewhere private without permission.
The list of summits is those which meet the criteria (in the UK P150). Whether you can physically get to the summit is not our problem. The summit may be private, or on a firing range, or contaminated land or religious land. Or maybe you can go there without anybody caring. But the access limits do not affect whether it is a P150 summit. There are summits which have had restrictions removed and summits which have had restrictions added. The MT do not add and remove summits depending on access, only that they meet the association criteria.
This means you can have valid SOTA summits that cannot be activated at present. There are 2 in England I am aware of, Upper Park and this one when it goes live. There are thousands of summits where access is forbidden, lots in the US and VK for example.
The RHB have determined the summit is now on the restored spoil tip. The AM has given notice the summit will move to this new place and given 6months notice so you can visit the old one. Whether the new summit is accessible is not the AM's concern, he has done everything perfectly by the book.