What he means is that the game was late by three years when released. It should have been released late 2020/early 2021.
So, the two years you mentioned are already in.
And meanwhile we are already another half a year past release.
I know, what he means.
But: who said, the game should have been released late 2020/early 2021? That was a business plan, a estimation, no promise.
I played long enough in my life to experience, that planned release dates are .... nothing.
Cities skylines is a big project. A very complex one. And it's obvious they underestimated the amount of work remaining until release. So 2023 wasn't the year we wished, you're right. It was just the year, which was a little bit(!) more realistic. Additionally it might have been still a little early.
There is a time, when you have to let go the game and give it to the players. But that doesn't mean, that it's ready. No, that just mean, that now all that problems and errors come to the surface, which were hidden until know. In the depth of librarys or behind operational blindness.
The two years I mean, started with the release.
And 2032 we will see the next identical loop with CS 3, which will be perfect 2037. I hope, I will see it.
But first I will give feedback for CS 2, enjoying it to go along, while it is riping.