If i have read and understand the Game informer article the game will be about Molag bal trying to conquer Tamriel and it will be set one millennium before skyrim. Obviously this would have been written down but there isn't any books or notes about this in the games. How are they going to explain that?

Maybe it was Scrapped from the History books and everyone forgot. Maybe its just a Recon. Or maybe when he invaded the hero prevented the invasion so it never happend and so nobody knew?

IIRC this is around about the time of Daggerfall, everything can be explained by it being deleted by the dragon break. (unfortunately)

There is TONS of lore about these events in the games....you're not looking hard enough. There are a [censored] ton of books in the game....and I've read them all since Morrowind. Go read up buddy.

This is way before Daggerfall.

skyrim is 4E201,
3E is ~433 years long
2E is 896 years long
I guess youre right it means that exactly 1000 years is ~2E600, however theres nothing going on in the timeline then.

The main problem I have is that Sotha Sil made his deal with Molag Bal and other Daedric Princes at the end of the First Era.

How then is Molag Bal going to be active in TESO? before any cataclysmic events occur to destabilise the power of the tribunal, or the barriers between Mundus and Oblivion? Unless this section of history is going to be totally retconned.

I thought most recorded information was destroyed at some point in the early era's?

I would love to know about a book which states that Molag bal tried to invade Tamriel or even attack it (except for the attack on Gilverdale).

PS i have also played every game since Morrowind but this book might have slipped away from my memory.

Maybe the Temple struck it from the records?

Makes sense, if Molag Bal only attacks Morrowind, and nobody else hears about it.