The short answer is "No".
The Flintstones has been remade, revived, spun off and revamped soooooo many times over the last 3 decades that I honestly don't see why we would need another Flintstones series. However, if someone were to produce a new Flintstones series, it should definitely take place before "I Yabba Dabba Doo" and "Hollyrock-A-Bye Baby". Perhaps it could take place during Pebbles and Bamm-Bamm's pre-teen years (the only time of the kids' lives that hasn't been focused on, IIRC). Pebbles and Bamm-Bamm could get some story lines now and again just to get a break from the usual "Fred schemes behind Wilma's back" shtick. Overall, however, regarding a new Flintstones project, I would say new shorts or specials, maybe, but a new series, why?
As for The Jetsons, apologies in advance to the shows' fans, but here it is: The Jetsons is over rated. There, I said it. I always thought that the futuristic setting was cool, but that's about it. BTW, Futurama owns the The Jetsons. George and Jane were pretty bland characters, when you get down to it. Elroy had the potential to be interesting, but more could have been done with him. The only Jetsons character that I had any real interest in was Judy, and that was for slightly different reasons. And don't get me started on those horrendous Jetsons shorts directed by John Kricfalusi. Plus, all of the attempts to revive the series have been pretty bland and forgettable, so definitely no to a new Jetsons series, unless whoever would be in charge of the project could actually make the series better. The Jetsons should just stay buried in the era in which it thrived.
I have to say this also; while I'm all for nostalgia, overall, I'm more interested in seeing what new shows have to offer as opposed to bring back all of the old shows from yesteryear. I'm not saying that every old series should be forgotten, but not every old show needs to be revived either. My only real issue is that there are many "old schoolers" who won't even give the new shows a chance; Is it really more preferable to see a bunch of old shows get revived than to experience something new that could potentially be good?