If this is indeed how it works, that is some grade A bullshit. Pressing the uninstall button seems and should be pretty unambiguous in what I'd like to happen with that software.
Considering that one of the biggest complaints I see is that you can't move UWP apps between computers and have to re-download them, it seems like Microsoft can't win either way.
It might be easier to think of it as being "uninstalled" from your computer/profile, but leaving the "installer" files on the drive after doing so, then clearing them if free space drops below a certain threshold.
At least that's my understanding of how it should work, if it's using Delivery Optimization. As I said, I've not tested/confirmed it myself.
Edit: Another reason to not immediately remove the files from the drive if there is free space, is that many people don't know that you can "reset" UWP apps rather than having to reinstall them. If you were trying to reinstall
Gears 4 for whatever reason, and it immediately deleted the files, you would have to wait for another 133GB download rather than reinstalling it locally off the disk.
I'm not saying that the system is ideal by any means, and if that's what they're doing they should explain it somewhere, but it's not necessarily a bad idea so long as it frees up the space as required.