Ok...
Ok,,,
Well, that's... unexpected.
It took me a moment to process this news but after I put some thought into it, I conclude that:
1) For me, the best part of ME3 was its multi-player. I accumulated a good 1K+ hours so far in it. So, since Inquisition's co-op multi-player seems to be in the same vein as ME3's then all I can say is that I am a happy panda right now.
2) I am very glad that there's no PvP, and am also quite happy that [according to that IGN video in the original post] Inquisition's co-op also sort of mimics ME3's MP connection to the campaign (to a certain extent). That is to say that Inquisition's co-op characters we'll play happen to be part of the Inquisition's "army", doing side missions "off the screen" for the Inquisitor. Which is comparable to the ME3 MP's characters being N7 agents sent by the Alliance to fight Cerberus / Reapers / Collectors "off the screen" as Shepard does whatever he/she's doing during the campaign. And that could help with a certain sense of immersion (that's good for the players whom are more comfortable when there's a minimum amount of role-playing elements included) for Inquisition's MP, even though its primary goal is obviously a to be a mode for fun, without too much to do with the actual campaign (which is fine, but having that small connection with the Inquisition's army is a neat thing).
3) I'm hoping that there's going to be character customization. Not just colors and patterns, but also various outfits to choose from (or collect as part of the loot table), weapon skins perhaps, or also character's icons/avatars, and possibly more. As far as facial customization goes... well that might be sort of useless in a MP mode. Because obviously you won't spend your time standing still to look at your character's face, nor would other players do so when a bunch of demons and blood mages try to burn you alive.
BUT...
More Importantly
I only hope that Inquisition's MP will be supported for more than just one year. I love ME3's MP but the amount of obvious bugs still lingering in that game mode is just a testament to what happens when you leave your game behind in the dust (well, its multi-player portion anyway). I do feel that the Inquisition team will be supporting the game for "some time" after release. How much time... that's of course impossible to say but I'm hoping that it will last longer than the one meager year that ME3's MP team disposed of to support it (they did a good job during that time, I'm not saying that nothing happened during that year, but I'm saying that a couple of extra months or another year beyond that point would have tremendously helped).
Anyway, I'm happy with this news, it's a shocker but in a good way.