The EULA can not justify removing gameplay options especially given their long standing declaration that they "build on the past" as part of their key change management principles. Arguably, they have broken that covenant/mandate they set themselves.
[EDIT]I have just checked - there are no such "get out" clauses for them that can justify the removal of features.[/EDIT]
The keys words there are "that they set themselves". There's no 'external' requirement for them to retain any feature of the game - otherwise every nerf coukd be considered as a breach of the EULA.
It sucks, but it's done.