New Heroes From Other Blizzard Games

Hi,

We all see how Overwatch characters are in Heroes Of The Storm and non "gust" characters from that game (and any other game from Blizzard) in Overwatch.

My question is if you can pick a character from any Blizzard game and have them be a gust hero in Overwatch, who will that character will be and what class they'll be in?

Please help.

I didn't find the right solution from the Internet.

References:-
us.battle.net/forums/en/overwatch/topic/20754545461
Creative Video Content

Thanks!