Well, I certainly hope they don't announce MEA to suddenly be open world (or semi open-world like DA:I). That would be silly, and would probably result in your despised fetch quests. It is possible that the quote you referred to is meant to mean that MEA will simply be using Frostbite 3, and they'll be borrowing the knowledge the DA team developed whilst using it. At least, I hope that's what it means.
Inquisition was not a bad game by any stretch of the imagination. I'll agree it was lacklustre in areas (I'm looking at you PC controls and combat in general), but it had a strong and compelling storyline that tied in exceptionally well to Asunder and The Masked Empire novels. It's a pity there weren't more refernces to Last Flight, but perhaps there is room for DLC for that. Also, what with volume 2 of The World of Thedas released, the lore behind Corypheus and The Architect is absolutely fascinating - it makes listening to Corypheus' perspective so much more intriguing. It's surprising how unique he is, especially in relation to The Architect, although it's a pity they didn't further explore his relationship with the Darkspawn.
The music was great (and, less subjectively, really well mastered. You don't always get soundtracks mastered this well in video games. The master puts ME3's to shame, which wasn't a bad master in itself).
I put in about 125 hours for a single playthrough, and I can tell you right now that I spent much more than 6 hours on story related content. The ratio of story to side-quests, although weaker than ME2 and 3, was perfectly fine in my opinion.
For me, the real weakness of the game was its lack of impactful consequences regarding your choices, but every single Bioware game that I've played (all since Mass Effect 1, except KOTOR) have had the exact same weakness. Not that that makes it any better, but it suggests that MEA will likely have the same weakness, unfortunately.