Of course there will be plenty more to drop, but here are the number of cards of each collection under the Legends and Flashbacks that don't have collection awards (other than like one or two) and the parenthesis is to have at least 75% of current cards...
Primes: 28 (21)
Signature Series: 19 (15)
Awards: 33 (25) Does Not Include Home Run Derby
Rookies: 34 (26)
Breakouts: 36 (27)
All Stars: 38 (29)
Veterans: 33 (25)
Post Seasons: 22 (17)
That is 8 different collections while last year there was 7 needed for Honus.
They showed players league, hrd, prestiges, and prospects, you’ll more than likely need at least the collection reward for these
I would be surprised if we need the homerun derby Griffey. I don't even think there's enough cards in circulation for everyone to have that done unless they are going to release a ton of them soon or people will start paying 200,000 for one card. I could see them saying collect four or five of them. Is there a prestige collection reward? I'm not aware of it.
I am with the others thinking it will require a set amount of unique legend and flashback cards. I dont think it will require percentages of particular card types. Just what my belief is now that they showed prestige cards involved. I dont think they would be stupid enough to further alienate their offline only playerbase.