I can see that, but it just seems like such a betrayal of Chuck. (More from Nate's side then Blair's.) On the other hand, I do think they resolved the Nate/Blair relationship too quickly last year, so maybe they'll get some closure there.

and another reason could be that writers are out of ideas on Chuck/Blair, hence the secret society plot for Chuck and Blair's pointless expulsion..

I honestly think that's a part of it. They're not letting Blair and Chuck interact al all, which is just ridiculous, but I guess they're out of ways to stop them from making out. ;)