Going a bit further, it seems like there's a grain of truth here, HTTP/2 has a stream priority dependency mechanism [1] and this report [2] from Imperva describes an actual Dependency Cycle DoS in the nghttp implementation.
Unfortunately that's where it seems to end... I'm not that familiar with QUIC and HTTP/2, but I think the closest it gets is that the GitHub repo exists and has a `class QuicConnection` [3]. Beyond that, the QUIC protocol layer doesn't have any concept of exchanging stream priorities [4] and HTTP/2 priorities are something the client sends, not the server? The PoC also mentions HTTP/3 and PRIORITY_UPDATE frames, but those are from the newer RFC 9218 [5] and lack the stream dependencies used in HTTP/2 PRIORITY frames.