a. They rewrote the whole "Pocket Guide to the Empire" just so they could make change how Cyrodill looks in Oblivion. They are willing to change the lore at will to fit whatever they want, I think that IS a problem.
b. While this might be a "Fun" mod, it just reminds us that the current Dev Team doesn't really care too much about the "Lore". It wasn't needed.
a and b are two different things. I
do agree they shouldn't have changed the lore, it comes over as a cheap way to solve problems. As an example, I'm missing the freaking cool sounding vampire powers from Immortal Blood. BUT we're talking about the space core here, something which happened to be a simple and pure easter egg from Portal 2. Conclusion?
Of course it isn't canon! Neither is it "needed". An easter egg
never suits the story, it's more like a nonsensical reference to something either inside or outside the same universe. Just for fun, you know? Plus, it's downloadable content, not something they forced in the game! >_< I really can't understand what you're having such a problem with, to be honest ...
Really, I hope you never played the Sierra games (King's Quest, Space Quest, etc.) back in the '80-'90s. They contained quite a lot of easter eggs, especially parodies towards each other. If you'd taken all of these as seriously as you do this, you'd hated all of them.