The Galaxy S10+ renders had a mistake, which has now been corrected. No, not the dual selfie camera in a hole, its the rear camera that was the issue.
Revised Samsung Galaxy S10+ renders (unofficial)
The S10+ will have four cams instead of three like originally shown. Theres still no solid info on the functions of those cameras, but wed be surprised if it deviates from the Galaxy A9 (2018) formula: wide, ultra-wide, tele and depth sensor (potentially a Time-of-Flight module instead of a simple B&W camera).
Here are some more of the new renders:
Four cameras on the back (not three) 3.5mm jack Dual selfie camera
The other big change in the revised renders is that the bezels have slimmed down noticeably. The expected measurements of the phone are 157.5 x 75.0 x 7.8mm. Thats very close to the dimensions of the Galaxy S9+ (158.1 x 73.8 x 8.5mm), despite the screen growing to 6.4 (up from 6.2).
Theres no fingerprint reader on the back, its being replaced with an ultrasonic in-display reader. The four camera hump at the back brings the maximum thickness at 9mm. Thats pretty impressive, considering that in-display FP readers add a fraction of a millimeter to the thickness.