It is a shame those mentions have disappeared yes.
Fortunately I captured most of them
in a thread I originated just before Christmas with regards to the Squadron mechanics:
- "Elite: Dangerous lets you team up in multiplayer, with friends..."
- "Elite: Dangerous is the spectacular new online multiplayer space epic that allows you to experience the 400 billion star systems of the Milky Way galaxy."
- "... an epic multiplayer experience with you at the centre of the action."
- "...Whether you want to trade for profit between systems, take part in multiplayer co-op mission alliances, free-for-all group battles and team raids..."
All the above quotes were taken from the previous versions of the main game page or the store descriptions. MMO per se was never mentioned, but it was not really necessary given the above quotes.
EDIT: Ah no, my bad, the multiplayer online mention is still there in the store page:
https://store.elitedangerous.com/eur/
Elite: Dangerous is the spectacular new sequel in the Elite series of games. Head for the stars, take a ship and trade, bounty-hunt, pirate or assassinate your way across the galaxy in this massively multiplayer online space adventure.