From what I could find online, there are no plans to include websockets as part of HTTP/2 (according to this: https://webtide.com/http2-last-call/ ). HTTP/2 is meant to supersede all websocket use cases.
Hmm, do the HTTP/2 authors say that it supersedes WebSockets? The article you linked to says that there may have been a missed opportunity regarding consolidation of framing protocols, but that alone doesn't imply that WebSockets are obsolete. I'd assume HTTP and WebSockets would continue to exist as separate protocols, as they always have.