Is there going to be open world content ever? Have I missed news or anything related?

[Magis]

EX/BoP alone doesn't stop it, as I've covered multiple times in this thread.

It's not about not implementing it, it's about delaying implementation until a way toprevent RMT monopoly can be found. See my Open World Primal idea here

Ah, I read the last page.... but as Seif pointed out, this invalidates basically any content!

Very well then. However shouldn't SE remove all instanced fights too if mercenaries are a real problem?
Basically if the game has nothing the RMT wants then there's not really that they can add that we'd want.
Rewards are important. The only way to have them without them not being exploitable is having just solo rewards and no way to trade anything.

RMT is going to find a way regardless. From powerleveling services, instance clears, to money trading. I find it the weakest reasoning for why something should not be implement. A feature that is grindy or gated sure (though I don't mind such things myself), but "because RMT" is a moot point. If players want to do an activity (usually due to there being a reward at the end), RMT are going to capitalize on it too. It's up to SE to make countermeasures to stop RMT such as banning, bot detectors, and good netcode.