A person need to keep in mind that something can be considered "dated" one day and then totally fresh and "new" the next, depending on whether a big-name designer has put them on the runway. People are sheep and will fall for ANYTHING again - even Hammer pants. Anyone remember when HUGE leg jeans became popular? Along with enormous bell-bottoms? Yes, they can make absolutely anything come back again, including everything listed in this thread.
That's why I think it is so important to be able to assess yourself and your style when you look in the mirror. The skirts mentioned in the OP can absolutely work and not be immediately tagged as dated, IMO, especially since GP is on the younger side and is well-put-together. As long as items look intentional, I think a person can get away with a lot more than fashion dictates. And yes, even if something isn't in fashion right now, if you wait it will be. Mid-length skirts never really went away, especially for women of a certain age; the primary difference was that the current trend was short so it was difficult to find them in stores. But they were all the rage in the 50's, and also in the early to mid-80's, and pencil skirts have tended that direction forever. Tapered and cropped pants are viewed as very on-trend right now, but they were also a trend in the 50's and can sometimes recall Peg Bundy if a wearer is not careful. The point is that as soon as items flood store shelves, people buy them when they would have scoffed at the idea before they saw them featured at Neiman-Marcus. One day and one person's (designer's) opinion can make a dated item on trend, and my point is that YOU can mke that day today and make that one person be you instead of waiting for someone else to okay it.
If we live as a slave to trends then we cannot even comfortably wear our engagement/wedding jewelry, because there are obvious trends in that arena, too. But sometimes like IK said, people LIKE what they are wearing - even items that might recall another decade. As long as you wear it with intent and feel good in it, you can likely get away with quite a lot of things that would otherwise be pegged as "dated".