You'll never know til it's asked, so speculation is a waste of time - ask, and find out.
As for the site, MS knows about it - they've got links from the official game page. Furthermore, they DEFINATELY know about mods since Reynen had a storm some time back, whereby he contacted Microsoft over it all (supposedly, open to truthfulness on his part of course, but no reason not to believe him there).
So if they didn't like what was happening, they'd have done something.
They're not, so take from that what you wish
So, I agree, why not ask? Costs nothing, looses nothing afaik... after all, people keep saying it's all dead etc - so what's the problem
Now, whom to contact? That info is required, as is the ability to then formulate a well written letter that's beyond "c4n we hav leik teh source code 4 freelnacer, cos we wnt to h4x is properly leik! k, thx, bai"
Okay, perhaps people are far more eloquent than that... but, meh, you get the idea