Here are a few other points, some that even negate my first post - and all of this is deeply speculative.
I) Just because the LS is "changing direction" doesn't mean it is necessarily going to be the LF-1. It would be wise for Lexus to turn the next gen LS lineup into hybrid only, or potentially even BEV only. That would be bold indeed - and it could certainly remain as a sedan if this happened.
II) Iacono's comments also come in a year when we are expecting a new LX. Could they be foreshadowing that going forward, the LX will become Lexus' priority flagship vehicle? That would make sense given the state of the market.
III) Either of the above could happen with or without the LF-1: LS could become a hybrid-only or BEV model, we still get the LF-1 and we get a new LX. Or maybe between RX, TX and RZ, the LF-1 is off the table all together.
But let's consider a few other points. Right now, the LS is selling worse than the GS when Lexus decided to kill it - by about 50%. Many global markets don't get the LX and won't because of emissions. In those places, RX would be the most prestigious Lexus CUV... so it feels like some sort of premium CUV is still needed at the top of the pecking order. It needs to be something that can support batteries, hybrids and fits within the targets for lower emissions. That's not an LX in any form.
An LS-X or LS SportCross could easily share parts and platforms with the rumored Toyota Crown and Century CUVs, creating a much better use case for a next gen RWD/FR platform. Maybe even a revised version of GA-L. Aligning those products makes a lot of sense. These models would have the same type of synergy we see on TNGA-K with the RAV4 and upcoming NX, and Highlander/RX.
Above all, it seems like the writing is on the wall for sedans. Not only are they no longer the status symbols they once were, but they also tend to sell at a discount with lower profit margins. The ES costs as much as an IS and is as big as an LS, so Lexus may very well decide that 1) it's not worth further investing in the sedan segment when the ES is already a juggernaut and 2) the only way to stay there is with a platform-engineered product like the ES. This is actually a great placement for the ES, because it opens up more options like AWD, Direct 4, an "L" model for China, more luxury features, and beyond. It's just hard to see the LS succeeding into the future as it stands now, even if they make it hybrid or BEV.
Weigh out the business opportunities. Could Lexus maintain the LS as a sedan? Yes. Is it worth it for a few hundred sales a month, even if on a shared platform with something like the LF-1? Probably not. Lexus can scoop most of the traditional LS buyers with an elevated next gen ES, and the sky is the limit for sales with an LS-branded LF-1.
When I think about all of those things, I end up back at square 1: The LS changing into something we've never seen before, most likely a premium CUV.