BTW,all of the movies are related isn't it?
They are not canon to the tv show (with the exception of Pokrmon 2000). They are also not related besides the main characters, but the first 3 movies in the Sinnoh saga of movies were related (The Rise of Darkrai, Giratina & The Sky Warrior, and Arceus and the Jewel of Life).
The first two basically set-up the third while each having their own storyline which is what I am thinking will happen with these upcoming Black & White movies. What is a little confusing is that both feature Victini in the title so it will be interesting to see what it's connection to all of this is. And not to mention the downloadable Kerudio which makes it seem as though it will be featured in the movie(s) in some way. And that to me makes it seem like the Musketeer Trio will make an appearance somehow as well considering Kerudio is basically the unofficial 4th member of the Trio.
A lot of information to speculate with but not enough to confirm anything.