Interesting idea and a possibility but I think the removal of these diodes (and others elewhere on the board) was just a cost cutting exercise, they are on a lot of the early rev boards. Strong indications that the design of the original model Switch was rushed as a whole and they likely ran out of time in testing in order to get it to market and went belt and braces in terms of protection etc
Not sure I have the two different brand plugs anymore but Delta are a pretty big PSU manufacturer and typically well designed and good quality, I’d guess their version has all pins populated (even if the majority are NC)… that being said, there’s no reason that Nintendo wouldn’t/couldn’t specify or request Delta to use less to reduce costs further, so it’s entirely possible another rev Delta rev is out with additional unused pins removed or the chance of one coming out in the future