Well April 2023 is a key date here - that's presumably when they started final training a lot of these models.

We're probably able to conclude what we're seeing in public is about about 6 months behind what's happening in development. We know that in the past OpenAI relied on a lot more lag.

Point is innovation is certainly accelerating but also OpenAI's time-to-market is shrinking (/shrunk - it probably can't get much shorter).