I don't have any insights into the post-pandemic picture, but up until early 2020 when I was working with flight tickets, the general pattern looked the same: roughly 90 days ahead is the best time to book.
I think it generally depends on the market and on the route. I got some cheap flights in South East Asia in the week I flew, with prices being lower than average. This led to me postponing “what’s next” decisions to the last possible moment.
Yeah, I think it applies mostly to long distance flights. You can see the effect you just mentioned in the graph in the article! The price < ten days immediately before a trip, when it's steadily creeping up, can still be below the long-term average, cheaper than almost any other period beyond the 30-60d window.
