[npinsker]

I don't think so. I see its pitch as "the best kind of exercise is the one you do", maybe preferable to playing a game, but not an efficient way to learn. How useful it is to you will probably depend on how effective the sounds and streaks and home screen notification stuff is for keeping you motivated. Personally, I'm motivated by quick progress and outcomes (streaks don't do anything for me), so Anki is actually stickier, though I must be in the minority.

Because they focus so much on beginning learners for whom nuance isn't important, this change doesn't seem like it'll hurt them.

[morkalork]

Being successful at Duolingo was always being like that guy who wins scrabble tournaments in French and Spanish without being able to converse in them. It's just a game and winning at it doesn't necessarily align with being functional in it. Otherwise second language schools would have long been extinct by now.