Thanks for your enquiry.
Could you just confirm that you are asking if your neighbour can now back out of the "new agreement" and instead retain their "old right of way" over your land?
I look forward to hearing from you.
Unfortunately, any release of a Right of Way (ROW) has to be by way of a Deed, signed by both parties. Hence, unless such a Deed is signed, the existing ROW remains fully in force.
Therefore, I'm afraid that despite any oral agreement, your neighbours are legally free to continue to have the benefit of the existing "old" ROW.
The appropriate Deed releasing the ROW should have been signed before you then did anything about creating the new ROW.
I am sorry this is not the answer you were looking for, but it sets out the legal position.
If I have answered your question, I would be grateful if you could rate my answer.