This episode sure was quite packed with many emotions, most notably mixed feelings from Rikka, but surely a very good transition for a "flashforward" (3 weeks is by no means small), as it definitely is a better way to show a sharp contrast between episode 10 and 11.
I'm quite satisfied how they handled Rikka's complex feelings in there, without going too much on the flipping switch tangeant: as expected, she isn't fully "Takanashi Rikka" and still has quite some remnants of "True Eye of the Wicked King" tendencies, but it is a good touch.
Speaking of which, her efforts are quite cute and amusing: all of her 何 question variations took me offguard, so was Yuuta
Likewise, good to see Rikka doing the first step with her classmates this way. Not like it was anything hard, but the attempt itself is quite important (she surely was briefed quite well by Shinka).
I was expecting Rikka's mother not being discussed that much, but it is quite relieving they didn't ignore that part and did cover the fact that Rikka obviously doesn't have a grudge, but still can't go against her awkward "emptiness" from discarding her chuunibyou like that.
That said, Sanae got the utter short end of a stick, and I can see why Rikka was quite worked up, as she was also trying not to fall back in chuunibyou, but at the same time, Sanae is a friend, so having both on the balance dealt a certain effect, to which Shinka and Yuuta had to deal with sooner or later (which makes me wonder how Sanae's "graduation" will be, even moreso since she is a anime only character).
I'm pretty sure some people will once again blame Yuuta for the last part of the episode, but as far as the series goes, there is nothing left but to make sure everything does not go back to square one, and putting things straight with Sanae was the only practical option there. Considering how she absolutely ignored Rikka's struggle to stay away from chuunibyou, despite the bridge and club room periods, better deal with this, and it surely wasn't easy and pleasant for Yuuta either.
Now, I'm really curious how they will wrap things with next episode, considering I can't imagine everything to be normal by the end of the series, although having full chuuni would make the recent events a tad... moot then.