"Better" is relative. To many, the FA would be better, to the majority, the MA would still be where its at. The things being asked for in the FA will please only some; they would ruin the MA however. There are plenty of players that just want some faster action. They are, at least at times, willing to chuck the "battle for land" and variety that can be found in the MA for a simple intense brawl.
Could be.
But I'm not entirely sure a FA would be really 'better for many', because seeing how the MA operates, and how the people in the MA react, I'm guessing that the popularity of the MA comes from the fact that it is an integrated arena of sea, land, and air.
Sorry for the long post, but this is what I think about the issue;
*People more seriously oriented to A2A fights do not really care about the land-grab aspect of the MA. They probably care only as much as it would help secure, undamaged bases to up planes in, and hold a stable ground to ensure consistent A2A combat. However, the more time I spend with AH and the MA, the more I'm driven to think these 'A2A folk' are a dying breed in the MA.
Most of the MA folk like the MA because the fact that there is much to enjoy in a single platform. Most of these guys are barely average in A2A skills alone(barely average in EVERYTHING, for that matter).. and yet, they still can find a purpose and feel needed by the team.
* They like the competition, and they like how they can become a part of something bigger. They may be sucky pilots, but when they move with the horde, they become a valauble asset in providing the main strength of the horde - numbers, literally. If fighting A2A is much too hard for them, then they can always up a Osty or M16 and park on the field, and shoot at the attacking enemies. Or, they could go to the CV and up PTs to scout the area, or up LVTs to help capture.. or they could up bombers and spray bombs on the enemy field.. etc etc.
Up with a horde and look around you - 90% of your team mates in that sector will probably die out within the next 15 minutes. Up in GVs and 90% of your friendly GVs will be busted as they reach enemy base perimeters. These average guys, are what consist the MA. Despite the fact that they are only average, they consist a part of a bigger force that ultimately captures bases and wins territories.
* Now, imagine a fighter arena. No doubt some of the better pilots and prestigious squads will have a smashing time in it. But would the rest of the MA-folk want to go there? Every time they up in the FA, they will be shot down like flies. They will die again and again, same as in the MA, but this time, they have no purpose to do so. It doesn't help with any strat or tactical maneuver because there aren't any in the FA. As soon as they realize the A2A competition is much more intense than the MA, and they can't cope with it(unless they become an ace pilot themselves), they will be faced with a choice;
1) stay in the FA, keep facing the humiliation and frustration of being shot down again and again.. and then become a good pilot
2) return to the MA. They are sucky pilots, GVers, gunners and etc etc.. but at least in the MA, they are a part of something and have a purpose to fight and die. They will feel good, if their feeble attempts somehow payoff and kill the last remaining FH or townbuilding, and your team mates get the capture. And etc etc..
* The point is, the very fact that there is much going on at the same time, is what keeps people in the MA. AH is undoubtably an flight sim game, but not all of AHers are A2A purists. In fact, most of AHers are people who enjoy the universal combat that resembles WW2 action in some way - air, sea, and land.
So, if the FA opens, will people go there?
My guess is, all of the people who were bored with the MA will go to the FA. Just like all of the people who were bored with the MA, and thought the CT would be an alternative, showed themselves in the CT.
But after one or two years, soon they will realize they will only meet the same people again and again in the FA. Under the same circumstances again and again.. even the greatest of A2A enthusiasts won't stand for fighting in the same arena, same conditions, against same enemy pilots again and again. It's basically the same thing as flying in a boxed-game multiplayer session.
* The MA is not fun for many A2A enthusiasts because it lost its balance. And
I believe the MA still can be made more fun - retain all of its good points, and still provide a good and intense A2A fight, and regulate the lameness and dweebism that ruins gameplay for many. IMO, ultimately, a FA is gonna hurt AH, more than anything else.