What's especially odd about the program guides at CTW Archives not containing info on episodes 846 and 847 is that the guide for the last week of season 11 says that people can re-use their old guides for the reruns and that a schedule is included for when the reruns will air. Considering that, I'm surprised they would print out new copies of the old program guides.
By the way, Muppet Wiki now has info on episode 846 (from trusted sources).
Last week the wiki added a full guide for a season 11 episode, after seeing all those season 11 guides I wondered if it was a full rundown (even if a lot of segments weren't detailed beyond what they're supposed to teach), so I looked and saw that some segments in the episode are not noted in the guide in any way, a handful of segments are in a different order, and there's at least one instance where a topic is mentioned as having four segments but only has two (whether back-to-back-to-back or spread out). And THEN I noticed small print on the pages saying that those program guides were compiled before the final edits and that some segments would be listed in a different order or not appear in the final broadcast at all.
Hmm, now I wonder if Sesame Workshop continued to send out program guides during rerun season, for those who might not have had them, and if they'd edit accordingly (like, if segments were in a different order from the final broadcast, would they correct them before sending new copies?).