The shows they are now airing at 9 & 12:30 are from Season 31, which was very similar to Season 30, but not as many classic clips, unfortunately. It would not confuse kids if they saw those 2 seasons, but Season 25 was very different. I see that you said "as long as Elmo's still around." But I think the main reason why kids didn't like Season 25 as much as the newer shows was BECAUSE it doesn't have Elmo's World. And unfortunately, that's pretty much all they like now.
Noggin is only still airing Sesame Street altogether because it's something they have to have, but they don't really anymore, since Noggin is no longer owned by Sesame Workshop. I don't think they even like Sesame Street, because it's too old-fashioned, and they want to do more modern things. I think they only still have Sesame Street because of Elmo's World. And eventually, they will probably just make Elmo's World as its own show, and cancel the rest of Sesame Street.