Yeah, but it was still considered a mini-camp and I think many, many players were there for it (and is basically that three week period where minor leaguers who arent invited to big camp have to scrape). Separate from the major league invites. From 2/17 last year:
Herrera is technically in the Phillies' mini-camp with other minor-leaguers. He dresses at the minor-league complex, not in the big-league clubhouse, and works out with other players in the mini-camp. But each and every one of those players is eligible to play on the big-league side, and in Grapefruit League games, at any time. If Herrera tears it up in mini-camp, he could push for a look in Grapefruit League action — and possibly more.
Here's the tweet from last year, 12 guys in major league camp, 19 guys in mini-camp. So, bigger number this year, for obvious reasons (including the fact that the would-have-been major league invite guys who can be there are).
https://twitter.com/phillies/status/1361729456956710916?lang=pt
(Also funny to see who was in mini-camp that wound up playing in the majors: Paulino, Vierling, De Los Santos, Hammer, Williams, Herrera. Plus you had Stott and O'Hoppe not yet ready for a proper major league invite.)
I think the distinction really does have a lot to do with money: you get less per diem and housing allowance (if any) in mini-camp. It goes up once real minor league camp starts. Meanwhile the major league invites are living larger.