The LG 32UL750-W is HDR 600 and at only $750 it's not going to have FALD (nor is dimming mentioned anywhere on the product page). So it seems FALD is far from a requirement for HDR 600 certification at least.Without FALD or OLED you really can't do even fractional HDR properly and it's marketed as a HDR 600 monitor.
That said, tftcentral reports that a HDR 1000 version of the panel used in the XG438Q is also on the way, and that could have FALD:
Of other interest is a planned new 43" sized panel based on VA technology. This will be a new panel sector for AUO as sizes for gaming displays start to grow and grow. This will offer Ultra HD 3840 x 2160 resolution with 144Hz refresh rate, and a flat format instead of curved. It was expected to go in to production during Q4 2018. There appears to be two versions of this 43" panel planned, one with VESA Display HDR 600 certification and another with HDR 1000. The latter could well be combined with a FALD backlight given that spec, although this has not been confirmed and is not necessarily required.