I'm a co-author on the paper: I would personally indeed not use the phrase "we can break Wi-Fi encryption", because that might be misinterpreated that we can break any Wi-Fi network.

What we can do is that, when an adversary is connected to a co-located open network, or is a malicious insider, they can attack other clients. More technically, that we can bypass client isolation. We encountered one interesting case where the open Wi-Fi network of a university enabled us to intercept all traffic of co-located networks, including the private Enterprise SSID.

In this sense, the work doesn't break encryption. We bypass encryption.

If you don't rely on client/network isolation, you are safe. More importantly, if you have a router broadcasting a single SSID that only you use, we can't break it.