terenz-
I think its just miscommunication. This has been the policy for a while. What they're not saying is that you get '2' bonus upgrades for 20k.
For example, 8 for Gold Preferred flying 10k, 8 for flying 20k (but with a bonus of 2 or total of 10). Instead of saying it that way, they're saying '8 and 10'. The way they say it does sort of imply bonuses of6 and 10, as opposed to totals of 6 and 10, doesnt it?