I don't think they're deleting the ability to do dungeons with other people. We can already do old ones undersized by ourselves already and it certainly doesn't seem to stop everyone rushing into Tam-Tara every single day.

It's similar to the NPC system in FFXI, which certainly didn't stop me grabbing some living, breathing friends for non-boring activities. Do chocobo companions ruin the game?

Personally I'm looking forward to dressing my squadron up and making them do my bidding.