As for the story Larian has in mind, it's clear that Mind flayers will have a big part to play in Baldur's Gate 3. Asked why Larian is focusing on the Cthulu-like brain eaters, Vincke says dryly, "They're Mindflayers, they're cool. They also have an element of Spelljammer to them [a 2nd edition campaign setting], which is a personal weakness."
Vincke goes on. "They have a very interesting history. They used to have a big empire before they were destroyed. Now they're in hiding, they're in the Underdark. All of the Mindflayers are after the grand design: how to restore their empire. So you have a very nice storyline there; very easy to understand background for creatures who have a good motivation to do things. But then when you start fooling around with it, there's a lot of things you can start doing with them."