Yea, Croc is def coming back in the new world; Oda wouldn't specifically have panels about him and Daz leaving for the New World if he didn't mean to reinclude him.
I don't believe it'll be as an enemy though, either. But yea, he'll be back, along with Gin. Enel is the wildcard here and I'm not sure why he would be back / for what purpose.
As for Fujitora, let's ignore the movie for a bit (because we're not sure if they were actually introduced as Vice Admirals, wiki beings wikis and all). The marines with pink / purple themes are Coby (hair), Hina (hair and clothing), Momonga (clothing), Strawberry (sword hilts), and Yamakaji (during enies lobby he had purple spots on his coat), Jango (clothing), and Fullbody (hair). The marines with feline type qualities are Tsuru (girl), Hina (girl), and Lucci (devil fruit).
I'm not too inclined to believe Coby is an admiral (too soon, movie said he was a captain). Same with Hina, as she was seen to be weaker than Smoker pre timeskip (she admitted she lost to Luffy during the war) and she's been introduced as his classmate, so at best she'll run even with him, not surpass him. She also already has a difference color epithet..."Hina the Black Cage." I think we'll all agree it isn't Fullbody or Jango lol.
That leaves Momonga, Strawberry, Yamakaji, Tsuru, new guy, or random VA with a new pink / purple theme as options. Honestly, with how much random facetime Momonga has gotten, I'm starting to think it might be him (he also just looks like a Fujitora to me lol). Strawberry did get facetime in the FI arc during the flashback, so I wouldn't be too shocked if it was him either. We don't know anything about Yamakaji so he is a wildcard, and I think Tsuru is just too old to seriously be an admiral at this point.
So Momonga, Strawberry, Yamakaji, new guy, totally off...what do you all think :P