Well, you're not necessarily losing that year in hockey because your draft picks often stay in junior or college for a year or two (or in Europe for that matter), and they certainly do when they are picked in the 20s. But I think it's more about the Flyers not needing to win now (and the Eagles almost always being win now because they're actually good). They didn't want to start the development clock on two players (and their ELCs) this past year and they also knew they weren't ready to wheel and deal this past year.
I also don't think it's going to be hard to get something "worthwhile" for one of these picks. Any competent young NHL player is still worth more than an uncertain 30th draft pick, and certainly any RFA offer would be. A trade-up/compression just depends on what the that looks like, and for whom. I still think trading the 30th pick for two seconds (maybe one this year one next year) perfectly reasonable too.