Playing on Samsung odyssey G9 32:9, 5120x 1440. rtx 3080 - I have played 2 Bot slayer matches, and neither have had a crosshair\ reticle while both ADS and not ADS. I am positive this is a bug, and not a feature. Although, not having a crosshair will raise the skill ceiling I do not think its intended.
Okay, so this is related to HUD horizontal Display Margin, anything greater than 0 obscures the crosshair, first distorting it with just a few ticks, completely removes it 5 ticks in or greater.