I'm not sure if I agree on the old system trivialising combat, though. Sure, you can put a lot of wits on all of your team... but where is your damage going to go, then? Your constitution? (Assuming constitution ends up having real value, in contrast with how it works now)
If you have enough wits to go before everyone else, chances are you've cut your damage by 1/3 if not more - which signifiantly decreases the opportunities for oneshotting.
I suppose this is just a question of exact numbers and it'd require extensive testing. But I would still hope for modding support for the old initiative system so both can at least be compared by the playerbase.
My rogue Sebille had very high Initiative and did a lot of damage. "She's a rogue, duh" - true, but I suspect you can make other builds that can achieve the same thing. But I agree that this is hard to talk about without testing the alternative system with most if not all of the encounters.
Given the fact that console games need to be certified well in advance means that it almost certainly is too late for changes.
If nothing else, this is food for thought if Larian makes a new Divinity game. I really hope they keep making games like Original Sin's.