Don't know if I'm going to expect anything because I feel that'd put a lot of pressure on them. With Gomes, Greenwood and Garner though you've got three actual footballers. I don't think we'll see much of Garner compared to Greenwood or Gomes, not this season at least. The more I see of Gomes in the first team the more I'm convinced his height won't hold him back in the slightest, he's too good of a player, if anything his low center of gravity is an advantage. His agility is unbelievable, you can tell the players he looked up to as a kid through his dribbling style.
I want to see a lot of Greenwood and Gomes next season because of how dynamic they both are, they're both good enough to make an impact on our attack now to be honest. With Greenwood as well, you're not just adding a great footballer but a fantastic athlete which obviously Solskjaer seems to be adding to the squad (Wan-Bissaka and Daniel James point to that). I don't think they'll be starting loads in the PL but they'll be on the bench plenty and have their chance for proper game time in the cup competitions.
Chong looks a million miles off to be honest, I think he'd suit a loan. He's not as good on the ball as the other three so he looks a lot more raw, he needs time to hone his technical skills.