I think your link is broken. It's sending me here:
https://bestcarweb.jp/news/scoop/115458
Also my hot take: Whaaaaaaaaaaaaaaat
Also by different grades, do you think they mean above and beyond the top level packages/interiors currently?
If they made the IS a refresh, the only way it could be mitigated in my mind is if it's a "refresh" with the option to turn it into a small, aggressive LS (limited engine options aside, for now).
You'd be covering 2 sets of niches (small super luxury vs small entry level luxury) with one vehicle, which also accomplishes what MB has been boasting the benefits of (our C class is made more attractive due to similarity to the S class), while also going above and beyond in interior quality to actually be a small LS and not just look the part (the C class is like if you were sitting in an S class and turned the graphics settings to "low").
If they could take the cost of the fully new model, and instead just redeploy to develop these options in a capital efficient way, they could pass the savings to the buyer so that a kitted out IS with LS spec luxury treatments and functionality would still be lower than the LS would start, effectively usurping the GS in some ways and leaving the ES to be the attractive, mid-sized option with nice but reasonable appointments and could double as fleet service vehicles.
I am beginning to think that the whole concept of the "LS+" from a couple years ago, coupled with the insane plans for LIDAR/sensory array kitted out LS test mules, is pointing to the highest levels of "L" Lexus models seeing further upmarket grades as well.
Build out the LS into the proper, westernized Century counterpart through 5 figure options packages (vs nickel and diming you as the europeans do).
Build out the LC, through grades and the LC F, into either a very nice lux cruiser with a NA8 or TTV6/performance hybrid, then give it options to spec it out to be super lux, or go to the LC F and go performance, no back seats, competitive machine.
Bring in a CUV equivalent to the LS, create a category of "lifted panamera", like the LF-1, and give it the same sort of treatment.
That level of choice would immediately, and possibly in a more capital efficient way, add a multiplier effect to the number of markets your hitting.
The germans tried to do it with a million different body styles.
I wonder if Lexus will instead try to go that route with longer-lived platforms, but significant and meaningful optionality on different models which could independently be refreshed over time ("the 2025 IS has a 3 new options for interior choices, 2024 only had 2!"). You're basically replicating the Apple model of incremental change with visible differences to drive desire to have the latest and greatest since it's so visible.
It could also drive more investment in modular design and construction, while still allowing for creative designs at the highest levels (easier said than done, obviously), potentially allowing for Lexus to offer more personalized vehicles (i'm shoving my pipedream in here for Lexus quality vehicle customization).
/speculation