No, certainly not.
The movie, I think, will be the midpoint and highpoint of the show.
Just because one season was of lesser quality doesn't imply that Seasons 7-10 will also be bad. Plus, after the movie is over, Meghan McCarthy will be back on the show. She has been away for all of Season 6 while working on the movie.
Plus, there is so much potential with worldbuilding, new villains, adventure, magic, etc., in Equestria. It would be a true shame to stop the train while it is still rolling. MLP has only recently gotten good after the premiere of Season 4. I've been following the show since its inception (for me, around S1 E3).
I am quite excited for what the show has in store for us.