The Frostbite-hype started years ago. It's always the players, not the devs, who talk about it and seem to wait it like it was the next Santa Claus. At best, you might have read or heard some EA-guy say "we'll look into it", which in PR-language translates to "No".
As noted above by Pschibra, a new engine doesn't guarantee a better game-play. Especially in a title that is recycled yearly it will probably cause a lot of bugs and glitches. Why change the cow when you can still milk the old one?
I believe the main reason why many players would like to see a new engine is that it would offer something different. The game would change without a doubt. After nth year of the same power forward meta many players would just like to have something different, and I can't blame them. The changes could be made without a new engine but it would take deliberate decisions and actions from the dev-team to do so, whereas with a new engine it would merely be a consequence.
To me, the changes and new features look very cosmetic. If that stuff took a year to develop, I wouldn't hold my breath for a new engine within the next decade.