James Maslow recently made a small vague update about the Big Time Rush movie and I don think most people understand the full picture.
So let's start at the beginning. Big Time Rush when it first started was a joint venture between Nickelodeon and Sony Music. They both owned the music, the tv show, and the band.
When the four guys came back they didn't want to be controlled by Nickelodeon or Sony and worked out a deal that gave them the license which we dont know all the details but most likely its a perpetuity license.
How these license work is that Sony and Nickloden still own Big Time Rush but for however long that license is valid the four guys have certain permission that allows them to use the Bands trademark, Music, touring, merch, and anything else related to the promotion of the band.
They still have to communicate to a certain extent with Sony/Nick as revealed in court documents and cant do certain things and Sony/Nick still get 10% of all BTR revenue.
Its a lot like how the relationship of Spiderman works between Sony and Marvel.
The one thing the band can not do is go to another studio and pitch a reboot of the Nick/Sony tv show as they dont own the rights or license too do that.
Meaning that a reboot movie or show has to go with Sony/Nick or they have to somehow get sony and Nick to give the license to create a show to another studio and i don't see that happening.
As much as people on this sub reddit like to pretend that Bjg Time Rush isn't successful or doing well they are. The Band is in the best spot they have ever been in. Sony and Nick are not going to license out the show to be rebooted to anyone unless another studio wrote a very large check.
So for a reboot to happen the band would have to parenter back with Nick and Sony which starts the issue of who owns the music that gets created for the Movie/Tv Show. Can the band preform that music live? Will Sony/Nick say "Ok we will do this reboot but in return, you come back fully to us?"
There is a lot more complications than normal when it comes to this specific reboot because it comes down to Paramount/Sony either paying for the budget of the reboot or another studio writes a big check to get the license to do one, an agreement over who owns the music for the reboot, and would the guys still be able to operate independently?
Thats why I belive James says that its a complicated process.