I'd wait to see the %'s before starting to scream about perking this or perking that.
To make an 'intelligent' reply, as opposed to a 'witty' insult- I don't believe the La-7 will be perked. The only reasons that people have come up with that may be a justification for perking a plane are : superior performance, rarity (IRL), or overusage. Which of these criteria HTC uses to perk planes is unknown. We don't even know if it is one of these criteria.
While it is perfectly clear that the La-7 does possess superior performance vis a vis any other nonperked plane, there remains the issue of "Well, there will always be a 'best' plane"- perhaps the La-7 is the 'limit'. If a plane comes out in the future that is better than the La-7 it will be perked, if not it will become a free plane. I suspect that when the Ki-84 is added it will be a free plane. HTC needs a plane (or planes) that are better than the rest, or people simply won't play. That is really what it comes down too. Most people who fly the fast planes aren't very good at traditional 'dogfighting'- which is why they fly the fast planes. Most people that fly the La-7 are even worse pilots, they need the La-7 so they can fight on even terms with the pilots of the Dora's and P-51s. So, in my opinion the La-7 is a crutch, but it is a nescesary one. If the La-7 wasn't in the game, and there wasn't another plane that was clearly superior to the rest, a lot of the people that fly it would simply quit playing- which is bad for HTC.
Overusage isn't an issue, the La-7, P-51, and Spit IX have been holding steady at about 10% usage apiece, the F4U-1C was at ~20% when it was perked.
Rarity in real life isn't an issue as far as I know, the La-7 was a fairly common late-44/early-45 fighter.
What does confuse me is why the Ta-152, F4U-4, and Spit XIV are perked. None of this planes are better than the La-7 in my opinion. None of the action in the MA happens at altitudes above 12k (on the outside, I'd guess 99% is 5k and below), so none of those perk planes will get into their 'comfort zone' where they are superior to the La-7.