To me it shows that first of all, they're likely further in development with characters than we thought they initially were. If Toon Link is ready to be shown, no doubt characters like Wario, Captain Falcon, Ness, Dedede, Meta Knight, Diddy Kong and others are too, these character are obviously of higher priority, but they just haven't had the chance to show them off yet.
Second of all it shows that he prioritizes things differently than us. Toon Link was guessed by the majority to be on the bottom of the list, other characters that some people consider bottom-priority characters like Snake, Ike, Wolf and Lucas could possibly be helped by it.
Finally, semi-clones like Wolf, Lucas and Falco are definitely helped by it, since it shows that Sakurai has no problem with these characters being here, and these 3 are a lot less cloney than TL is.