What some people are failing to realize here is the process on how the show is made. They do not decide from the top to have this sketch and that sketch and only work those ones out. Generally, they'll finish the writing day with 30-35 sketches. Those will get table read, at which point they'll cut to about 15-20. At that point they will start the production elements necessary (props, non-live shooting, etc.) and maybe a few of those will die before Saturday.
On Saturday, a dress rehearsal, complete with a separate audience, is done at 8 PM. This will generally feature some extra sketches. Recently, they've been putting the ones that are cut on Hulu. Based on what aired and what was cut, they were obvious choices since they fell flat. Three of them were more recurring characters of the returning guest stars (a Debbie Downer sketch featuring Betty as Debbie's grandmother, a Bronx Beat sketch and that Molly Shannon character that I can't remember). The fourth did not have Betty at all.
So the chance that Betty was in every sketch was not unusual and not unprecedented, I think Gabourey Sidibe was also in every sketch on her show. It's just that the skits they decided to keep, she happened to be in every one. And for the questions "why wasn't there a game show sketch", there very well could have been, but it didn't make the cut. More "shocking" was the absence of a Golden Girls sketch, in an interview Rachel Dratch mentioned one was written and was at least rehearsed during the week, but that didn't make the cut either.
And, hate to disappoint you Matt, the "surreal, out-of-the box" last sketch was a reworking of a census sketch they did in 2000 with Christopher Walken. As much as SNL has been relying on stock characters this season, this was not uncommon for any sketch show (Carol Burnett, I'm looking at you). At least it's not as blatant as the Jack Benny Show, which would sometimes take an old radio script, spice up the gags with some visuals, and make a TV episode. The only time you really don't see a reliance on stock characters is when they have a large cast turnover, and they haven't had one of those in 15 years.
--Mike