Tracey was completely original to the anime.
Why would Max not be considered a main character? Because he had no Pokémon of his own?
I guess you got me with Tracey, but he was a short-lived main character in an entire region completely original to the anime. None of that has ever been repeated, which probably means they were just experimenting after Pokemon's initial success.
As for Max, that's exactly why. He wasn't a Pokemon trainer. He wasn't really that significant to the plot even though he was a "main" character.
As far as I'm concerned, the official anime formula is Ash, Pikachu, Male from the games, Female from the games, Team Rocket trio. The fact that Iris is in the games pretty much confirms this idea.
Hey, I registered to comment that I'm 99% sure it's just an Exeggutor chasing Chillarmy.
The Pokemon in the daycare is definitely not Exeggcutor.
First of all, I don't think they would be lazy enough to accidentally release a video featuring a past Pokemon. They have yet to feature any old Pokemon barring the special ones you get in the dream world.
Second of all, it looks nothing like the overworld sprite of Exeggcutor from HG/SS, which I assume would be the same in B/W since they kept the same style of "PC sprites."
Also, I highly doubt those were the evolutions of the starters a few pages back, although I admit I do like that final-staged Tsutaja