All the games have something to do with towers, but it is deep lore and I'm unsure if Bethesda will ever actually "use" it in-game by making the Thalmor try to vanquish the mortal plane. Myself, I think it would be a great main quest for some future game, to research the Thalmor plan and put an end to it, but how realistic is it to think that it's actually going to happen? Do you think Bethesda will have the courage to do it?

Will they try? Absolutely. Will they succeed in carrying it out? Pretty sure they will.

Will it actually mean they get what they want out of their plan? I doubt it.

All I know is that the current incarnation of the Thalmor need to be defeated and a true Aldmeri Dominion can rise. Thalmor-run Aldmeri Dominion

Well, as it stands, it's my understanding that we don't yet know exactly what the Thalmor's plans are. There is much evidence to suggest that they want to take over the lands of the Empire and reinstate elven authority over Tamriel. But, regarding their more abstract and metaphysical goals, we have only the hints of some creative types and fan speculation to go by.

It seems very plausible to me that the Thalmor, driven by the belief that Mer are the fallen descendants of the Aedra, want to unmake the Mundus which, to an extremely reactionary elf, would seem to be a prison of earth and flesh, thereby enabling them to reclaim their divinity in Aetherius. But, I don't think its been confirmed that that is what they are after. Until it is confirmed, we can only theorise.

With their demanding the abandonment of Talos worship and seizing part of Hammerfell, it is painfully obvious that they hope to use the White-Gold Concordat to cause infighting among the races of men and consequently weaken the Empire, softening it up for conquest (something that at least some people in the Empire have noticed and are drawing attention to). But, as far as we know, their plans do not extend to anything beyond the mortal plane.

I think Bethesda would be silly not to capitalise on fan-thirst for closure on the issue of the Thalmor threat we are still left with at the end of ESV: Skyrim and war between elves and men feels inevitable in universe. It might just concern the devs though that putting hundreds of NPCs on screen is incredibly difficult with contemporary tech (without causing slowing/crashing etc) which is the only way to build a convincing on-screen battle without the advantages of explosions and aircraft available to modern war games developers.

I agree though that stopping the Thalmor from unmaking the world or erasing humanity would be an awesome main quest for the next single-player Elder Scrolls title.

The Thalmor are already executing their plan. Why would they be rounding up Talos worshippers in Skyrim?

Also, MK has already written that the Thalmor will win in the end. And before people remind me that he is an ex-developer, one ought to remember that he has worked with Bethesda under contract and was involved in KotN and Skyrim. He was also the one who wrote the Thalmor in the first place.

Furthermore, it's been theorized that every game has been concluded with the Hero destroying a tower which holds the world in place. Everything seems to be leading up to a Thalmor victory.

MK already outright said the Thalmor win. Like Darksun said, it doesn't necessarily mean they'll ascend back to the et'Ada like they're trying to, but they'll most definitely succeed at breaking the Dragon until it's mended in C0DA.

They're doing it already.

But my understanding is that the towers are useless at this point after the events of oblivion. So doesn't that kind of thwart that idea?

Towers aren't just (or necessarily at all) protection against daedric invasions. They're more than that. The only thing that Martin's sacrifice abolished was the necessity of the Dragonfires.

I'm a bit busy, so I'll just link to http://www.imperial-library.info/content/nu-mantia-intercept, which discusses the purpose and importance of the Towers (White-Gold in particular) at length.

https://www.youtube.com/watch?v=2rvEHJ0heR8#t=197

...or at least we'll see them try then, I guess. Wouldn't like their victory...

Isn't C0DA treated us fan fiction anyways? The description of TES Community Creations is
your art, fiction, "C0DA", and other TES-related content inspired by the universe of the Elder Scrolls.

That said, its hard to tell whether or not that he's actually planning to enact (Though I doubt he had any communication back home to begin with) their plan via the eye, or he was just on a major power trip.

But yes, the Thalmor are already carrying out their plan. The Concordant and subsequent ban of Talos along with hunting worshippers down contests to this point of their ideals.

I suspect that'll be the case. This idea of the lore being "open source" also allows Bethesda to do their own thing and deviate from some of MK's weirder out-of-game work. Well, they could always do that anyway, but now there's a lore justification for it.