The other 20% of FS9 users will purchase KLAX after it is AES'd.
Another statistic a bit "in the clouds"...we haven't been able to see a measurable sales "surge" of a scenery that never had AES for years and was heavily requested (Cloud9 EHAM, for example), that would really make any difference along the lifetime of a product.
Yes, there's some kind of a "mini surge" in the first month after AES support is released, but after a while sales goes back exactly to the same levels as they were before AES, I don't think having AES impacted for more than 10% of overall sales for the whole lifetime of a product, Cloud9 KLAX never had AES.
The only case were having AES or not might do a difference (forget doubling the FS9 marketshare against FSX), is if there are two competing sceneries of the same airport, with the same quality, one with AES and the other without, AES might shift the balance in that case. But if a scenery is visibly better than another one for the same airport, people will always choose the better looking/performing one in any case.
So, the actual 20% might become (maybe) a 22% with AES...