I don't see how free technologies or terracotta army bonus are in any way logically similar to extra policy slots. That argument is quite a reach.
I have never claimed that these are the same, all I have said is that the same thing is happening for all of these wonders.
"Player finishes construction of Wonder X so he gets Bonus Y. If Wonder X is conquered by player Z, then player Y keeps the Effect of Wonder X and player Z just gets the yields associated with the wonder, but not its main effect."
I made this example because people claimed that in all other cases except for extra policy slots the bonuses change ownership, which is obviously not true as proven with the examples I gave, and that it would be odd for a wonder not to provide "any" benefit when conquered, yet, such wonders* already exist - again proven by the examples I gave - and have never caused much uproar). That does not mean that the bonuses are the same, it just means that the claim that no other wonder works this way is simply incorrect.
(*"such wonders" within the limitations outlined in my last post, the main effect doesn't transfer, the yields do.)
But again, I'm even open to the idea that the wonders should be changed, I think both implementations make sense depending on what you want. Which basically boils down to uniformity of rules, or more interesting gameplay. So it's still not a bug no matter how you look at it.
Calling it a design flaw however... yes, if you are on the side that thinks more interesting gameplay trumps uniformity of rules, then calling it a design flaw makes perfect sense for you.
It's a design flaw in the same way 1upt is a design flaw for people who really hate to play whack-a-mole with the AI.
And if most people agree that the benefits of one system totally outweigh its negatives then it may very well be an objective design flaw.
Which, at least with the small sample size of this thread, may very well be the case given that I'm basically alone, arguing against a horde of people who don't even seem to be able to see the other side of the equation while not even being on the side of totally wanting uniformity of rules over better gameplay.