You asked how stuff can be removed from a remaster and still be called a remaster. I explained how that can be so.
The Special Edition in particular is relevant because Lucas changed things based on decisions he made later. Removing the Erotica bonus is equivalent to making Jabba a CG slug in his scene in A New Hope rather than a human gangster, as he was originally envisioned (yes the scene was cut from the theatrical release but the footage of human Jabba still exists). It’s a change in artistic vision that the creators want reflected in their new definitive version.
With any luck Capcom won’t pull a Lucas and make it nearly impossible to get the original version if someone wants to play it warts and all.