Pre Skins
I don’t think this is the best place for suggestions.
Anyway, it was confirmed that you can’t buy the new legendaries from HoT, it will be just from craft.
About the old precursors, I really doubt that they will change how the skin unlock system will work.
(and the other 8 elite specs maxed too)
The reason it was done the way it is, was because a number of people made legendaries before the wardrobe patch came out, and they deserve their pre unlocks just as much as people who craft today.
Any character logging in for the first time since the wardrobe patch (even now) will go through their skin unlocks. This is not a completely rare occurrence either, in addition to people who took breaks, it also applies to several military personnel I know who were deployed.
I don’t think there is any way for them to make the skins unlock differently depending on how the legendary was acquired.
A legendary you bought from the TP is identical in every single way to one you made yourself. There is absolutely no way for the game to tell them apart. It might just be possible for them to add some kind of flag to legendaries when they’re traded to enable the game to tell them apart, but it would be a lot of work for a fairly minimal benefit that would probably upset just as many people as it would please.
“Life’s a journey, not a destination.”