They should be the gold standard for production values, and art budgets, and editing, and anything else that can be improved simply by the application of money. But for subjective things like lore, there's no guarantee of the same.
In fact, I think I'd go further: when it comes to lore, WotC basically can't be the gold standard. The thing is, any art worth the name is going to offend someone. And WotC's need to pitch to the mass market, and to do that for every product, basically means that they can't risk that - they will necessarily have to play it fairly safe. Which means there will never be a "Game of Thrones"-like setting from WotC, or even something as 'mature' as the 3e "Book of Vile Darkness". Indeed, with things as they are, they would never have originated "Dark Sun", or "Birthright", or even "Dragonlance".
(And yes, I'm aware "Dragonlance" is on the schedule. There's a difference between dusting off an IP you own and originating a new one. Besides, every second conversation about DL seems to feature a major subthread about what problematic material they're going to excise.)
If you're wanting new and exciting lore, you're probably better looking elsewhere.