Duchene is likely getting $8M per, the Uber video was done last year and it might have been childish statement it really doesn't hurt his value. Sens are a terrible team, he still had a decent season given the problems. Finding a possible 1C or strong 2C, especially when inferior players playing lesser position in Kane and JVR snagged $7M deals.
Sens if they want any value need to entertain a trade sooner than later. I don't believe they've even discussed extension, but given the cheap owner will unlikely offer anything near MV which could only drive his trade value lower.