The CL-650 is fully capable. But I’m unsure which ARTCCs, if any, on Vatsim are offering en route CPDLC. My understanding is there may be some facilities that will sign into Hoppie and offer PDC via ACARS, but it’s going to be controller-dependent, hit and miss. You’ll have to check their controller info every time to see (or just try it, I guess). To be sure none of it works like real life FAA CPDLC.