The Studio isn't that inaccessible - if you look at the second Max tech video, where the guy knew what he was doing, he had the cards out in a jiffy. Since it would have to be an official Apple upgrade it might be "authorised service agents only" on the pretext that stupid people might lick the power supply - but I think that was an option with the iMac Pro.I haven't seen one, but I expect that it's a LOT more accessible than the ones in the Studio.
(I think it's kinda a lame excuse - third parties have been selling RAM upgrades for Macs with exposed internal power supplies since forever, even back in the CRT days when there was 15kV floating around long after the power was disconnected, without getting sued into the stone age every time someone won a Darwin award, and if it's that easy to fry yourself, it's just bad design as Apple are putting even qualified service techs at risk. Any future "right to repair" legislation better take that into consideration, or it's going to be trivial for companies to dodge )