I have seen Russian telegram channels vociferously refuting that a lieutenant general was captured, and showing additional photographs of the actual lieutenant general in which he doesn't even really look that similar to the captured officer. Yes, they do look similar, however, that doesn't really mean much. Also, I would assume that if the Ukrainian army really had captured a two-star general (Russian lieutenant generals are equivalent to American major generals, they are actually two-star, not three) they would emphatically be talking about it way, way more than they have been. It would become the main media story for days.
But of course, this is just my speculation; I don't actually know anything.
And yes, 911, this is, at least for now, the biggest Ukrainian victory since the first couple months of the war. We will see if it lasts.