I'm all for the 2017 one, but it really would have been great if we got another one with Rick O' Connell. A prequel would have been cool or something that would have extended his character. Other than three movies and an animated series, we never even got an ongoing comic book other the one that was cancelled after 1 issue (2001) and a massively forgotten one in 2008.
Whats the point? We already know his story and it would just be filler material. Also you wouldnt be able to have any supernatural elements in it, since that wouldn't make any sense with his character in The Mummy being skeptical of the superstitious stuff.
I know I'm late to this thread, but I agree wholeheartedly with the OP about how a prequel on O'Connell could have made a pretty good movie. And to the poster who said that there couldn't be any supernatural stuff, it'd actually Evie who, at the beginning of the first film, is skeptical about curses and such. O'Connell is the one who believes "there is something out there, something underneath that sand," as he tells Evie on the boat. Granted, there couldn't be anything in the prequel like him unearthing any more mummies or on par with that, but as we all know a film doesn't have to have supernatural elements to fun and enjoyable.
All that said, I doubt such a movie will ever happen now. However if it were, what with the rate at which digital de-aging technology is coming along, Brendan Fraser could come back for at least part of the movie!
I'd want to watch a prequel that was 100% set on the night before The Mummy wherein O'Connell has "a very good time". Just one big, farcical, action-crazy romp.