Robert wants to cameo in a new Elm Street, but NOT as Freddy...
http://bloody-disgusting.com/movie/3393215/robert-englund-wants-return-elm-street/
IMO, there would be no point in having him in another remake/reboot/re-calibration/reconstitution or whatever you want to call it.
If he's going to be in any new Elm Street, he must return as Freddy.
Pushing 70 or not, if the director and production make things more comfortable for Robert, such as lighter silicone makeup that takes less time to apply and remove but still looks legit, and easier work hours, then I don't see why he couldn't do the role one final time.
Seeing him NOT as Freddy in another Elm Street, will be like seeing the original Ghostbusters cast NOT playing themselves in the new horrible remake.
Come on producers!!! Do something that the fans would die for! Make a real sequel, or just a final movie that doesn't have to acknowledge any of the movies past the first three, and bring Robert back to show the newbies how it's really done!
Also, please blatantly use my ideas here on IMDB, and some of the other good ideas from different members, and we'll be thrilled, at least I will :)