There are HD CRT tvs. I have a Sony Trinitron that's HD. It isn't 1080p and only accepts component cables, but it is HD.
But I think flat screen LCD tvs are fine for the Wii U.
Component cables cannot do HD, the cables cannot transmit the data fast enough. It's the sole reason HDMI exists... Also I don't think it's possible to have HD CRTs, although I don't know what CRT technology really is so I am not sure.
I have already said this in many, many threads but...
Games that lag on HDTV is because either the game, the console or the cable does not transmit HD graphics and as such there must be a conversion into non-HD and then a conversion into a resolution the HDTV can understand. 2 conversions which take time and thus lag. (And there might be extra conversions if the game doesn't match the console or the console doesn't match the cable. But, normally games are made specifically for a console's resolution and the cables on the console are made specifically for the console's resolution, obviously).
The Wii U outputs in HD, Smash was made in HD, the HDMI cable was created to transmit the HD settings. As such as long as your TV is natively HD (meaning its not a cheap TV that only "upscales"), there will be no conversion for this game and thus there will be no lag.
Obviously it takes a lot longer to render 2073600 pixels than it does 384000 (almost 6 times longer!) but the time it takes to draw a pixel is very, very, very short. The lag always comes from conversion. So, no, Smash 4 won't lag on HDTVs.
Quite frankly if Sakurai did not make a 480p or less output option then using component cables on a CRT (or an HDTV for that matter) will actually lag the game. And it's very possible they did not include said option as gaming nowadays is completely in HD.