Yep, really doesn't have an autothrottle.
The CRJ gives advisory VNAV only but does not act on this. Since this is the case, the devs haven't modelled this functionality in the sim, although may add in later on as an update, but the effect of not including it is small as it won't control the aircraft.
This aircraft is a real stepping stone from something the ATR 72-500 to the more advanced systems in say a 737.
Don't forget the CRJ grew out of a business jet.