Here are some 2018 HO scale ideas.
Locomotives:
Stepney
Murdoch
Stanley
Thomas (Green Version)
James (Black Version)
Henry (Before He Went To Crewe)
Arthur
Daisy
Stephen
Hiro
Flying Scottsman (With both tenders!)
Rolling Stock:
Rocky
Judy and Jerome
Gordons Green Express Coaches (re introduction)
Red Express Coaches (re introduction)
Spencers Special Break Coach
Narrow Gauge:
Duke
Sir Handle
Peter Sam
Duncan
Blue Narrow Gauge Coaches
Luke
Millie
Flatbed
Mike
Rex
Bert
Bertrum
Victor
Non Rail Characters:
Kevin
Bulgy
A lot of these are nice ideas, but due to lack of recent appearances, pricing, and/or lack of popularity to warrant sales for a Bachmann model I don't see most of these happening. The only things I could see happening are Stanley, Sir Handel, Peter Sam, Duncan, or (possibly) Daisy. Stepney would be on there too if not for the fact that he hasn't appeared in full CGI yet. Same could be said with blue narrow gauge coaches since they only have red ones in CGI.
Mike,Rex,and Bert are not narrow gauge
I would like to see a black version of James.
I don't believe they will remake Henry in his old experimental version looking like Gordon. The new CGI kept his special coal with his modern look. Rewriting that Henry old version didn't exists keeping his small firebox.