I think this is a new angle and hope it is not in the mind-numbing category (not derogatory but complimentary in this context) of most of the previous posts. It is not in answer to any outstanding question, be it either still to be answered or of great merit.
As already stated the RJ needs (and has) a compressor just as does a jet engine. I suspect the reason for the initial observation that it doesn't have one is the belief that they are fundamentally different machines. The RJ and TF are just different breeds of the same with very similar cycle requirements but obtained from very different looking parts. I don't think there's any great stumbling block to be made of the fact that a conventional RJ doesn't work at zero speed but the TF can.
At zero airspeed the TF does no more than an RJ. It can sit on a test bed running at TO from Monday to Sunday (with slave oil supply) and it has actually done less than nothing. It has moved nothing, except the thrust cradle a few thou, but has cost a weeks worth of fuel/oil/cell occupancy/creep life/etc. Once it starts down the runway though, it has taken the first step to being a ramjet and the turbom/c compressor has taken the first step to being redundant. eg you can't use the SLS 43:1
PR of a big fan in an F-22.
The B777 at cruise has the same subsonic piece of compressor hardware as the pre-SCRJ, a piece of ducting. the only difference is that the rest of the compressor is downstream on the TF but upstream on the RJ.
I find it satisfying to look for underlying similarities rather than thinking there are fundamental differences.
To get the job done both the RJ compressor, with its attendant shock compression, and the TFC, with its supersonic regimes, treat the air with the utmost violence on the one hand, and then gently on the other, with the touchy subsonic diffusion in the duct or rotating blade rows and fixed stator passages.
The degree of brutality which the RJC metes out has always been foisted upon it by the missile cruise requirements. The turbom/c, on the other hand, has increased in brutality from the gentle subsonic compressor of a J79, for example, where the inevitable low stage
PR required 17 stages to get about 13:1. You have to thrash a lot more energy into the air if you want a compact HPC where 10 stages give about 20:1. The road to this level began with turbocompressors entering the RJ compressor regime by using supersonic blade relative MN.
Therein lies a similarity. It's high relative MN between air and pieces of metal that give you the makings of a compressor. You don't necessarily need relative motion between the metal of the compressor and its 'mother'.
But the conventional RJ still can't get off the ground!
Bear in mind that the TF only exists to cruise just like the RJ. It needs to be a 'different' machine to get there, in as much as, in its money making regime, it has different ratings, ECS bleeds, turbine clearance bleeds, etc. compared to TO and CL. A B777 won't economically get to 35000ft in its cruise 'config'. The TF is a hybrid.
So what if an RJ also needs a bit of hybridization to get to cruise.