With the CV rework, planes are more like regular surface units. There's only one of it moving about which is directly controlled by the CV player. However engaging the CV player is not like engaging other units, the CV rework teaser introduces a new AA mechanic called "sector fire" and proposes that becoming good at predicting the CVs movements is the "skill" to counter CV gameplay.

The key game mechanics of WoWs are lead/aim, enemy movement anticipation and being aware what is (or might soon be) shooting at you and not giving them an easy shot (i.e. proper distancing, angling, maneuvering, working your concealment/cover, anticipating focus, etc.). Being good at all of these allows you to deal heavy/devastating damage to other units while reducing the amount of damage you take. This aspect is missing in the CV rework.

Suggestion

I would suggest to make it possible to aim AA directly like you aim guns. That you can switch weapons like you would switch between artillery and torpedoes, you switch to AA and get an "AA aiming mode" like you get a "torpedo aiming mode".

The CV will need to anticipate focus (are there other units to distract his target), keep maneuvering (don't fly straight/level), use concealment and cover. In turn surface ship players will need to become efficient at shooting at planes, knowing when and how to shoot at them, anticipate their movements, be aware of where they might sneak up on them, and so forth.

Manual AA would make skill relevant in surface ship vs CV engagements on both sides. A skilled player in an AA ship should be able to devstrike a careless CV player just like a BB can devstrike a broadside cruiser or a CV can devstrike a careless surface ship player. This suggestion would make skill and mechanics symmetric. It would also make tactics symmetric, a ship could draw the focus of a surface ship player so that the CV can get in a strike, or a CV could draw the focus of a surface ship player so that a surface ship in trouble can get out of a jam.

Q/A

It's too complex to shoot AA

There are many games that incorporate AA gun shooting. To aim AA you need proper fuse time (if you don't have radio fuses) and proper lead/aim. You can automate the fuse timing part, so what's left is proper lead/aim (just like shooting other units).

It's too much to also need to shoot at planes

With the CV rework, planes are like other units in the game. There is only one "unit" per player, directly controlled by the player. It's not any different than shooting at other units like surface ships. You focus on what's most important to deal with right now.

You don't have any AA if you don't use it actively

If you are not actively using AA manually, there could be automated AA that's less effective. Games like steel ocean and navy fields used that system.

We wanted less skill gap, not more.

The "skill gap" refers to the current CV playstyle/mechanic and its issues. The suggestion aims at introducing skill to defend against CVs, something that has not existed so far, and in the current CV rework still doesn't exist.

What's wrong with DefAA, why not just give everybody DefAA?

DefAA is "press a button and maybe not get screwed". It's not a skill you can get better at.

Planes are in the sky, concealment doesn't exist.

Ships are on the sea, concealment can come from either distance (too small to spot), or from obscurance (they're behind something blocking direct line of sight). Both can and do apply to planes (and are in fact used in combat aviation) just like they apply to ships on the sea. Managing concealment is a key aspect of WoWs. Weather effects could affect concealment (and wargaming is experimenting with that). It'd be quite interesting to have planes hide in clouds and the like.

What's wrong with sector AA?

Sector AA might have a bit of tactics involved, but it's not a skill you can get better at. The CV on the other hand can get better at dodging AA and gaming the sector AA. You again end up in a situation of press a button and pray vs. another player using their skill. The problem the CV rework tries to address among other things is, that ships have no counterplay to CV attacks other than pressing a key and pray, huddling/badly positioning and reckless maneuvering while spotted in full view of a lot of enemy guns. Sector AA is only a minor step in the right direction, but it's still no effective skill based counterplay to a CVs attack.