Hardly. If it is up to par with Aff and Destro, it will be heavily gear dependant and probably not used for progression, but reasonably viable.
But anyone who remembers the ToT Unnering Vision of Lei-Shen knows, it wasn't just the imps, it was also the Molten Core procs that the imps gave you. Which was why Grimoire of Sacrifice was ahead with that build. It buffed Soulfire enough that it was worth not having a demon around when you were chaining soulfires together, fury or no, just to keep from capping Molten Core. I was running into those situations again with this trinket, on a target dummy. Get the Mythic version, and a fight where you can spread your Dooms around, and it will be as if Shadowbolt didn't exist.
Add to that that the Teir peices are 3 Haste/Masteries and 2 Crit/multistrikes, and we seem to have a Tier that is set up for Affliction/Demo, rather then Affliction/Destro.
All subject to mathing and PTR changes, of course. But my point is: there's no point in being overtly negative while the facts are still coming in.
Edit: And the Archimonde drops combined with the Betrayer set to fill in the missing pieces will be an awesome transmog.