Both share the same attributes: The spec allows them to work, but they require lots of effort on the implementation side to get it right. HTTP/2 require a library which does sane write scheduling and prioritization to make it work.
QUIC handoffs are a lot more complicated. They will require a library which supports all the necessary features. And it will require infrastructure which supports it. Without infrastructure support, packets from the client might get routed to the wrong host after a IP tuple change, and can from there on not associated with the QUIC connection.
My guess is some QUIC deployments will figure out how to make it work - others likely won't, since a lot of efforts is involved.