Yes, normal. I'm guessing the higher pressure helps keep the desired tire profile under the heavier weight of the car. I have the 19" Michelins and top them off about every 6 months or so (usually due to a warning on the dash), which then brings them up from 39~40 to 45psi (that may explain why my last set only got ~22K miles). Since you are topping off more regularly, keeping your average pressure higher and closer to spec, you may actually see longer tire life.
Question for dual motor owners: Are you finding tire wear more uniform between front and rear, or is there a measurable difference? For my legacy 2013 old fashion classic single motor Model S, the rear tires wear faster than the front (due to Regen only on the rear), so I wonder if having dual motors splits the wear more evenly..??..