As others have said, Nintendo basically threw out all their classics that they have access to without needing to license 3rd party titles. Earthbound Beginnings/Mother, Earthbound/Mother 2, and Super Mario RPG are really the last 3 and one of those is something Nintendo has to make a deal with Square to release (and the snes football game... lol). The remaining titles are either Japanese only (like FE2-5) or require some kinda peripheral and aren't an easy rom dump (duck hunt, yoshi's safari, mario paint, etc).
The 3rd party titles you'll continue to see are things that are really cheap to license for content (Jasco's games), or cost a bit more but the company is doing nothing with them (like Capcom's Breath of Fire titles).
I also wouldn't be surprised if Nintendo looks at the data and sees that 90% of people's time in NES and SNES online are just playing the super big classics that are already their like Super Mario Bros or Link To The Past. I imagine for the average consumer, you could probably cut half of the NES and SNES titles from the library and it wouldn't impact them. As long as they still have Donkey Kong Country and Kirby's Adventure to play they're golden.
At the end of the day you aren't paying $20 a year to access a netflix of classic titles, you're paying $20 to play online, and the classic games are just a bonus reward for people.