I really liked the original movie, and honestly, I don't think the sequel might be as epic as the first one - as long as it features modern day combats, at least.
A jet fighter movie about nowadays US Navy will be much more like Stealth, or even worse. The thing is, just like many others have already pointed out, a big thrill of older fighter movies are the dogfights. You can make 2 straight hours of aircraft going toe to toe, and will still be godamn good to watch.
But there are no more dogfights now. And I doubt the audience will be at the very least amused to see pilots look at radar screen blips all the time, fire a missile or two at an invisible target, watch blips disappear and call it a day. A movie about this has lost most of the actual joy of watching aerial combat, which is the adrenaline rush of seeing the face of your own enemy mere feet away - both of you being strapped to aluminum tubes, flying at hundreds of miles an hour, trying to machinegun each other down.
That's why I agree that it would make much more sense for Top Gun 2 to be set around the same time of the first - like, a few years later or even a few years before.
That said, I think the best fighter movie of the last few years was Flyboys. It explores one very underrated (hollywoodian speaking) historic event (WWI), and has got some bad ass dogfighting sequences.