I suspect the mix does not have LC and RC channels and whatever software you are using to look at the channel layout is incorrect. Why? Because their is no LC and RC channels in Dolby Atmos 16 channel system standard used for home systems.
Not using this Atmos decoder as the channel layouts do not support anything with LC and RC.
You could, of course remap the wides (LW and RW) to L and R, and L and R to LC and RC.
Actually, Dolby Atmos is object based, and is designed to be rendered/scaled to the number of supported channels you have in your home system. Several channels are almost always fixed, typically 7.1.2 (the standard 7.1 speakers + one stereo pair of overheads).
While typical AVRs and an upmixer like Penteo use a subset of locations (i.e. 9.1.6, with 7.1+wides, and it doesn't support Lc/Rc as you say), on the Trinnov Altitude, we can define any of the 24 floor speaker and 10 height speaker locations that Dolby Atmos supports (up to 24.1.10). Not 100% sure on this but Storm Audio's implementation might support Lc/Rc as well on their 24 and 32 channel units. I'm an Altitude 32/24 owner, by the way.
So you literally can have a 16 channel system with L/C/R, Ls/Rs, Lrs/Rrs, Lw/Rw wides, and Lc/Rc screen centers and two pairs of heights (i.e. Ltf/Rtf and Rtr/Rtr) if you want. My own system is 13.4.6 (4 subs), and along with the speakers I mentioned above, I also have a pair of front side surrounds (Ls1/Rs1) and another pair of heights at Ltm/Rtm. As far as I know, Trinnov is unique in supporting the entire set of possible speaker locations for Atmos, not just a subset that has been coded for DSP implementation of Atmos.
So yes, you can have Lc/Rc playing content that passes through those locations with moving dynamic objects. It's not common, but it exists. Gravity, Hacksaw Ridge, War for the Planet of the Apes, Unbroken, and Oblivion are examples, also Hunter/Killer, Moonfall, Overlord, and among other albums released in Atmos, REM's Automatic for the People. Not home to look into this, but some of the electronica albums on Apple Music mixed in Dolby Atmos use them as well - Yello's Point comes to mind.
It's easy to tell which speakers are activated on the Altitude - there's a Dolby Atmos Object Viewer that you can look at in real time which shows where objects are located, as well as which of your defined speakers are playing. if you don't have Lc/Rc, whatever objects would pass through those location snap back (fold) into the L/C/Rs according to how Atmos operates.
NB: according to the information on the Info tab for speaker constraints on the Altitude, the only requirement on the Atmos layout for having Lc/Rc is to have Ls/Rs, for some reason.