Are MP_PATH_(AVAILABLE|STANDBY) probing frames?

[MikeBishop]

The draft does not modify RFC 9000's definition that "PATH_CHALLENGE, PATH_RESPONSE, NEW_CONNECTION_ID, and PADDING frames are 'probing frames', and all other frames are 'non-probing frames'." However, it does say that "A PATH_(AVAILABLE|STANDBY) frame MAY be bundled with ... a PATH_RESPONSE frame in order to indicate the preferred path usage before or during path initiation."

This suggests that these frames might be treated as probing frames. Either way, the draft should explicitly state that they are or are not.

(Alternatively, the concept of probing packets/frames might be outmoded in a multipath world. This concept seems largely unused in this document except in Section 4.3.5.)