I expect Smoker to be an Admiral. He was already at least Vice Admiral strength IMO, before the time skip and I can see his attitude of ruthlessly going after pirates being something Aikanu would like and thus be promoted. I can see AIkanu looking past Smoker's bad attitude and disregard for superiors. Aikanu would like Smokers get anythig done regardless of what he RULES may be.
I wouldn't mind smoker being Admiral either, he has been seen as strong since day 1, he has never been beaten by the strawhats, and he has a drive to be stronger. I would much prefer it be him than some "SECRET" guy that was hiding and didn't show up during war. I find that option to be the worst imaginable. Reminds me of too many other manga's that some big bad shows up out of nowhere whenever the author needs a new strong enemy. Its hack writing.
The thing I love about One Piece is we have known about the 3 admirals since a long time, we have known about the 4 yonkou for a long time and he even gave us the supernova's early, we have the warlords, and lots more. We have so many people that will make viable opponents that DON'T just pop up out of nowhere. I'm sure there will still be fun surprises in the new world, but it will be cool seeing any of the above people come into the story ,because we alreayd have stuff on them.
I mean take BLEACH. Hate it or love it, you have to admit that if we knew about Ginjou or any of those people prior to this arc, it woulnd't have felt so bullshit. Or take the Vizards. If they would have gotten a cameo at some point say before Ichigo went to soul society it would have made their introduction not feel as forced either. Seems like everytime Ichigo gets a new power ,and it seems unique and special and even soul society members are surprised by it, all of a sudden a big group of people with that same power show up out of nowhere to talk to him. Just feel like ass-pull after asspull.
In one piece if we start a fight with Kaidou and in his crew he has now say Drake or Capone, it gives a feeling of sweet, look at that. I know that person, I'm excited to see that person fight whoever he fights. And that is just an underling of a yonkou who when first shown doesn't need any big story told because we already know about him. All we need is to see how he got on that crew.
Or if we see say Hawkings on Kidd's crew, then we all going "holy shit two powerhouses joined up" Then we can be excited about both and not be going i blind wondering how strong each guy in this new crew is.