this is if we are talking about previous passes. for upcoming passes, if such change was implemented, all skins could be sold for nemo bucks. if someone buys all pass tiers for 6400 nemo bucks, that contains four skins, those skins can later be sold for 1600 each. though this creates a problem, that if someone only wants the last skin, he will have to pay 6400 for a skin and not 1600. however he still gets all skins with all exclusive content from the pass like frames and nameplates, this stuff is less important
second option: skins can be purchased during pass independent of tiers. the tiers containing skins get skipped. this will make the price of skins the same during pass and after it ends, but it may make some people play less during pass.
although people would spend less real money during pass, with greater skin selection in item shop. people will also spend more nemo bucks, which may lead to some people buying more nemo bucks. but again, we dont know what will bring more money. if the developers explained to us their business model, we could understand better why they distribute skins the way they do. we can only say that those passes create the issue of people missing out on skins
