Abed Nadir of 'Community' may be the most tele-cognizant character in all of the TV Universe. He knows he's a character in a TV show, and he is familiar with all of the other TV shows that make up the dimension in which he lives.
He knows you're watching him.
And he likes it.....
As such, he tries to live his life accordingly.....
It would appear that Professor Ian Duncan is a tele-cognizant as well, but I think there's a splainin to keep him rooted in his own reality with no knowledge of the great secret of the Universe.
Abed said 'M*A*S*H' in response to Jeff's "Cheers" because he does know that "Cheers" is also the name of a TV show. (It could be a reality-based series about the bar back in Boston.)
But 'M*A*S*H' is a TV show as well, perhaps presented as a documentary series about the legendary 4077 mobile medical unit from the Korean Conflict. And Duncan, having seen both series, responds accordingly - as if he recognized Abed was speaking in some kind of non sequitur code.
At least in this mention, 'The Wire' could have been a TV show about something else - perhaps a science fiction show based on the creature that nearly took over the world during the coronation of Queen Elizabeth II sixty years ago.
(The Wire was not actually human in appearance. While trapped in that electro-video form, she took the likeness of a well-known British TV personality of the Time as her own.)
When British guests where I work say to me "Cheers" in thanks, I respond with "Frasier". It seems like the appropriate follow-up..... But at least I know I live in the real world.