heygoodfella,
You cannot have 800G FR4 TX without getting to 400G FR4 TX first. So yes we are waiting on 400G FR4 TX. With that piece and Poets small form factor 800G TX = 2x400G is enabled.
See the latest video at 6:58. It shows 1H 2023 release to production and sale 400G TX. Also shows 2H 2023 800G TX.
rogue