Thats just assumptions based on specs, until its done then nothing is sure, IMX477R sony sensor might have better chance to output raw 4k in 24fps but raspi 4 wont be able to spit it out to SSD fast enough according to some users , depending on whos talking theres various info about it.
But still, its only raw video feed, no mic.Probably no preview at all as that would drop fps.