Yes, the DX80 should, as any SIP or H.323 endpoint should also, work with the MSE.
The MSE 8420 blade itself is end of support as of 30 September 2018, so you're on your own and will not be able to get any official support through Cisco if you are experiencing issues, and it is highly recommend that you consider replacing it with something that is current and supportable.
Wayne
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