Well the picture is relevant seeing as it's the only picture of Toad we have in Smash 4. People take that Mii-verse quote too seriously and try to use backwards logic to justify Toad having a chance. That is a common disclaimer for any game under development. Sakurai said the exact same thing when presenting Mario VS Mega Man at E3. It's meaning usually refers to the fact that the visuals and power of each move aren't finished yet, not that they'll decide to completely change something last minute.
The Toon Link thing doesn't work either. Toon Link is a returning vet. Toad is a returning MOVE. The Link argument you brought up about WW and Spirit Tracks Link is also flawed. You can't say well, it's because WW Link got repped, not ST Link. Toon Link represents ALL young/cel-shaded/kid Links just as regular Link reps ALL adult Links form previous games. Smash doesn't have one specific Zelda series' Link. Yes they use the artwork of a specific Link, but that by no means means he's repping 1 specific Link. He's repping the series protagonist Link all-together, not 1 Link. Just as Toon Link is repping the fact that the Zelda franchise always differentiates an Adult/Child Link. There's 2 Links repped because they are 2 important versions of Link throughout his series. It just so happens that this cartoon style has become synonymous with the games featuring Child Link.
Toad is a species just as Yoshi is. Yoshi is just a lot more iconic to Mario itself, has his own series, and actively helps Mario instead of just standing there going, "Oh, Bowser got Peach again." "Here's a star for no reason." Etc.... Well until recently I guess since he's popped into the platformers again. However once again, Bowser Jr. trumps Toad in importance and appearances. Sure Toad has been around longer, but he doesn't really take active roles in most games, whereas Bowser Jr. has appeared in almost every major game since his debut and is a primary antagonist w/ Bowser in each one.