Rafale is not being used for Meteor development firings (all Gripen, AFAIK), & I think that no integration work has yet been done.
Mmm, not really:
Rafale has flown with the "ground handling training" version of Meteor (to test in-flight characteristics with identical weight, dimensions and aerodynamic shape to the real missile). This was done even before the Gripen firing tests, and before the same missiles were tested on (British) Eurofighter.
Unlike the "Meteor Avionics" test version, the "ground handling" version does not interface with the computers of the carrier aircraft, and only provides a "dummy" for aerodynamics tests.
These "dummy" tests have been performed both by land-based and carrier-based Rafales.
So-called "Environmental Data Gathering" (EDG) missiles for tests have also been flown by Rafales, especially to measure stress on the missile during carrier operations.
The full Meteor version will have to be changed for the Rafale anyway due to a different (one-way) datalink on the aircraft. I don't think the alternate datalink unit for the Meteor (for compatibility with Rafale) even exists yet, only the two-way datalink used with Gripen and Eurofighter.
(above see also Jane's Missiles and Rockets 2005)
Some of the above, in addition to stating the planned integration on Rafale can also be found in this
press release by MBDA from 2006.
Sidenote: Dassault has so far never integrated the AMRAAM into any of its aircraft; they offered integration on some Mirage 2000-5 export tender, but that was never realized. ASRAAM integration capability theoretically exists with Dassault, as they've sold the UAE Mirage 2000-9 with that. Similarly, the necessary technical specs for AIM-9 integration of course exist at Dassault (several Mirage versions integrated Sidewinder). However, the US would of course need to approve any integration work - or at least eg Raytheon, since the ToT (technical specs) already happened for eg AIM-9.