I was thinking about this issue the other day and I think people are being blinded by a 'It was in a scheme, but the scheme has ended so I can do what I like' mindset. The point about EIA legislation is that land falls under it regardless of whether the habitat was created on purpose by a scheme, on purpose voluntarily, or indeed accidentally......
.....So the 'It was in a scheme' argument is irrelevant. All that matters are the conditions on the ground and the actions the land manager has taken over the last X years. The reason for those actions doesn't matter. So if you join a long term environmental scheme that has the specific aim of increasing the habitat value of the land then there is a significant risk that your actions will eventually result in the land failing an EIA test.
I agree with, and can understand all that you say. However, in my instance ,where my agreement terminated a little before that of @ajcc, I was specifically allowed to revert the land, and it said so in writing.
It may well behowever, that EIA legislation may well trump such a statement... But the onus should be on who to prove that it is the case?