The really sad part of all of this is that the Toyota/Lexus hybrids are actually REALLY good at what they do.
We have a 2015 Lexus GS450h and a Tesla Model 3. The Lexus returns an average of 37mpg (calculation from fill-ups, not on board computer figure). That is absolutely extraordinary for a 350bhp petrol luxury saloon car, and in fact only 1mpg less than the diesel 2011 Volvo V70 we had before it, which was much less powerful and a diesel. That 37mpg REAL WORLD return from the lexus is way better than any other equivalent petrol car (eg BMW 535i (~26mpg), Mercedes E350 (~28mpg) (Figures from fuelly.com, 2015 model year, UK units)). It's really extraordinary.
Jewel (Lexus GS450h) | Fuelly
But the nonsense advertising really does put a black mark on it. It's an absolute shame because the technology is very good indeed.
There is a lot of misunderstanding of how the toyota/aisin hybrid system works, and it took me a long time to get my head around it. The "eCVT" is closely related to a rear diff more than a transmission and is incredibly mechanically simple, providing a variable gear system with very few moving parts, no clutches, bands or chains (quick version - where a rear diff has a single input shaft and 2 output shafts that can rotate at different speeds, the toyota HSD has two input shafts and the output shaft turns at a summed speed of the two inputs. With an electric motor on each input shaft then the differential speed of the two inputs (where one could even reverse direction) gives the output. The combustion engine is coupled to one of the input sides). This allows other tweaks like using a lower power-density atkinson (faux atkinson as the mechanical stroke doesn't change, but valves stay open later on compression stroke so that the expansion stroke can expand the volume more than the compression stroke compressed it) cycle, eliminating engine idling (the engine is never idle - if it's running while the car is stationary because it needs to warm up or whatever, then it is used to charge the battery rather than just "idle" - getting something is better than nothing) and stop/start that works without lag and no "cough-cough-cough Vrooom" starting - listen to a Lexus hybrid engine start sometime and you'll hear that it doesn't turn over like a normal car; it instantly starts running at stable idle speed with no over-shoot. The eCVT means that when the engine does run it is kept much more on the areas of the load/rpm map that are better for thermal efficiency, and the huge gearing range means that the GS can cruise at 90-100mph at 1000rpm (autobahn, of course). This is quite a contrast to how many other hybrids work, where they stick an electric motor onto the transmission of a normal otto-cycle engine and 6 speed transmission.
The thing about plug-in hybrids is that they get magic (fantasy) WLTP figures without going to all this trouble to maximise every last bit of ICE efficiency, so you have people driving around in Volvo XC90 T8s that get in the 20s mpg while patting themselves on the back for their low BIK. Adding plug-in capability to the Toyota/Lexus hybrids means adding more battery and then only getting as good as everyone else's WLTP cheating figures.
Again, I am NOT defending their borderline fraudulent advertising. I'm defending the talented people that thought the actual tech up and made it work so incredibly well.
As much as the toyota hybrid is perhaps the best combustion engine setup there (in terms of low NOx, low CO2, thermal efficiency, etc), it is simply the case that combustion engines have had their day. Sadly the first Toyota EV in europe will be deeply disappointing (Lexus UX300e - poor ride, very cramped, 50kW charging (in 2020? wtf?)), and self-benchmarking will convince many dealers etc that, combined with the "self charging" nonsense that EVs aren't worth bothering with yet. This will hurt them badly in the long run.
The actual OP in this topic though is more about what Toyota CS are saying about plug-ins, and I suspect that has more to do with poor product training for their support staff than a concerted, centralised effort. It seems that the CS swallowed the "self charging" bs so hard that now they can't untangle themselves as to what plug-ins might be good for.