I think the "same character does same segments" formula has been run into the ground ever since the Workshop realized their audience was getting younger. Children that age may need some order and regularity, but they also enjoy surprises: part of my enjoying Sesame Street as a girl included not knowing what the "sponsors" would be, how they'd be taught, or who would announce them in the end. With the same three or four characters handling most of the letter/number clips and announcements now...that surprise element is nearly gone.
Thank goodness for the few shows which don't use Trash Gordon at the end; having a character from the main story announce the things-of-the-day feels more traditional. Having the anonymous voice-over announce them while characters minded their own business felt even more traditional: the classic letter and number clips rarely used characters from the street scenes, so the things-of-the-day were beyond their control or choice.
I can recall only one exception to the unwritten rule "Thou shalt not choose nor question The Sponsors": a late 90s episode centers on Elmo's attempts to change the letter of the day from O to E. He barges into letter segments unannounced, begging characters to make "the first letter in Elmo's name" the center of attention. Worse yet, he rewrites some O clips to teach E and performs them alone. The anonymous voice-over still warns him: "The letter O won't go away...O is still the letter of the day." When the show ends, "Mr. Voice" (as Elmo calls him) suggests that the two of them cooperate; he points out that O is the last letter in Elmo's name, gives both letters equal billing, and mentions the number of the day (3) as an afterthought.
Granted, that episode makes my least favorite Sesame character the star and has a sponsor-driven plot (which I normally dislike). Yet Elmo acts like a typical child who'll try anything to get his wish; he even brags to "Mr. Voice" about how hard he'd tried to change things. (Since the show usually teaches that trying to do things independently is good, the voice-over agreed with Elmo.) Endings like those have a stronger link to the whole episode than the "Trash Gordon" clips do: his adventures rarely have anything to do with the sponsors, and the bedtime-story framework feels artificial when the main plot doesn't last a whole day.