there is already the Channel Analyzer NG (NG is for the "New Gen" version) that does something similar more or less. Well... much less to be honest but that's a starting point. The problem with LTE and WiFi is that they obey some very specific protocols and are not at all generic.
The Channel Analyzer is aimed to be a general signal analysis tool a bit like the basic E4404A. Maybe we could add a generic clock recovery for various phase and frequency modulations that would help getting the symbol constellation for most common modulations. At the moment you can duplicate the instantaneous phase derivative (that is FM signal in fact) and slide one against the other which produce in XY mode some sort of symbol transition constellation for GMSK and MFSK variants.
For specific protocols one could go deeper in creating a specialized plugin. Most of the building bricks are common: scope, scope controls, decimators, ...