I honestly think they should hold off on another movie for the following reasons:
1. Despite not having it's fans Movie 6 did set a pretty high bar in terms of quality, Movie 7 was a return to the standard and many fans felt underwhelmed until around Movie 9. Movie 10 set an even higher bar that think it would be a pretty bad move for Toei to release another movie that is nothing more than an extended filler episode.
2. The manga is going through a huge transition period where the status quo is changing all over the place. I think until the dust clears, the crew is reunited, and we have a sense of balanced out arcs again they should avoid making another movie.
I guess what I'm saying is that with the exception of Movie 7 all the movies since 6 have been creative and diverse ways in re-imagining previous arcs, exploring artistic license, and playing around with different forms of storytelling so I think Toei should avoid the "well despite what's going on in the manga lets ignore all that and tell a story with the current crew and maybe allude to Haki-power ups for Luffy while fighting generic villian Y" or "Hey, let's retale this popular arc and shift a bunch of stuff around". Water Seven/Enies Lobby may have been a few years ago but it still feels like "too soon" to make a movie version, and retelling the entire East Blue arc seems like a disaster waiting to happen.
O-chan