That person made quite a clever answer.
*Mega Vileplume confirmed*
Nah, but seriously... we all know there might be some good reasons for it to be mentioned. I've already read about it being related to a new, flowery legendary (Rose Parade, anyone? XD ), Shaymin, or AZ's Floette.
I have this weird idea (more like a HUGE STRETCH, but, bear with me). What if it actually revolves around AZ's Floette saving the world from (a possible) Mega/Primal/True Zygarde Rampage? I am one of those people who undoubtedly thinks that the silhouette is a new Zygarde form, but it looks plain evil, so maybe (another stretched hypothesis) with this new form, Zygarde loses control of its powers and starts to destroy nature instead of putting it back to normality. Floette can fit somehow with its signature move, and Kalos will sprout again. (And, yeah, I am open to strong criticism with this idea, so you can give me your opinion on it.
)
Or, it's just a metaphor of how the series will once again bloom with several new ideas, features and generations to come.
EDIT: Somehow, my comment appeared as if I had written it twice in the same post, so I just deleted the repeated comment.