I don't hold my breath on that.
I just checked for 128GB (which is already above what most people buy except for the Switch) and UHS-1 prices went from 20-60€. UHS-II started at 140€, and I couldn't even find just one UHS-III, let alone a SD-express card. Of course with such a price difference only absolute enthusiasts or people who absolutely need the plus in speed will buy the faster ones
Pretty much this. We might seem some positive impact on our day-to-day devices maybe in 4-5 years, ie when the price drops from the probably massive release day msrp's.