An interesting hypothesis. The modern PFD does have a lot of information displayed, and maybe not all pilots can assimilate it. However; even if not all displayed on one screen, all the information does need to be assimilated !
I think it could be the flight director that is leading to some of these accidents? The rookie pilot might get used to glancing at the flight director rather than looking at the basic flight parameters.
If the flight director has been given the wrong information, it might well be centred and the automatics might be following it - leading to the rookie pilot or the pilot with poor SA to think everything is OK. However, if they are not routinely looking "through" the flight director to check that the attitude, V/S, altitude, speed and flight path are all sensible and reasonable, then problems could arise and bad situations could get missed.
I wonder if going from basic training on C172 equivalents straight onto big jets, with their flight directors, is producing these problems in some pilots? Those of us who's first commercial jobs were in aircraft with no flight directors and no automatics, and who therefore spent years and many hours hand flying with reference to the basic T instruments in real life ATC environments, perhaps gained a deeply ingrained scan and situational awareness.
I can imagine that the rookie pilot who has received only basic and abbreviated training directly onto a LoCo modern jet might rely too much on a flight director and come to trust that if they believe they have programmed the correct route into the FMGC/FMS, then all will be well. But for example, if a short cut is given and the pilot does not mentally check their 3x table, and/or is not aware what the green energy circle display means, they might get into trouble.