I don't think BFI is the be all and end all solution, especially not when Sony's motion handling prowess is concerned, and I think the ZD9 is precisely where we have to look as possible proof of this (remember the Z's X1 Extreme chip caries over to the Sony OLEDs and 2017 mid range LEDs now).
Z9 review indicates that you can get BFI to kick in on the Z series once you amp up the 'clearness' to its highest setting, but as is known, BFI reduces the brightness and on the Z becomes rather flickery. The inherent nature of OLED technology may see it respond differently to the same settings, I'm honestly not sure, but the same menu options from the Z are quite likely to be there on the OLEDs if we want it since the same chipset is being used.
Again though, from reading Z series reviews there seem to be more optimal settings for motion. From AV Forums own ZD9 settings video for example, you'll see Steve highlight the preference for TrueCinema, and as you say yourself, raymondo, the Z's sample and hold motion performance (thanks to whatever magic Sony are conjuring there) is exceptional.
Bottom line really is Sony have a remarkably good history with motion processing which, combined with their expertise having already made their own 30" industry standard OLED monitor, really puts them at an advantage over their competitors here.