The story of creating the Immersive Audio Bitstream and other Standards would be a sensational modern story. But, the first rule of Fight Club is the same as the first rule of SMPTE Committee work.
Suffice to say, the audio immersive audio standards have been in process and in use by those with Atmos systems for a while, and it is time to send out DCPs with names that include IAB instead of Atmos and DTS:X and AuroMax. Any theater with a rendering solution that can play a DCP labeled Atmos can play a DCP labeled IAB.
And further, this can be said of any manufacturer which follows the standard.