Actually, i don't entirely agree with that view. If the panel is going to be wall mounted, then yes, you are right. However, if the panel is going to be stand mounted in front of a window that has full sun on it for a large part of the day, then defo the white back would be the best choice.
Much more likely to reflect more of the sun's heat than a black panel.
LG in particular use the extra heatsink on the 2022 G panels to help the screens brightness. Funny thing is though all the G panels have a black back....................but are only available with wall mounts as standard.........................i use my G2 77inch stand mounted in front of a window. I also leave the curtains closed all day while i'm at work. The reason you may ask ? because i know full well that the sun will negate that heatsink and make it useless after i get home and start watching tv.
So, black if you are wall mounting, white if you are stand mounting.