Competitors tend to do that. Originally Firefox used traditional version numbering up until 3.0, but then when Chrome came out with their numbering scheme of incrementing the main version number with every minor update, Firefox followed suit. It’s the same reason Microsoft called the Xbox successor the Xbox 360, if the average consumer would see the Xbox 2 next to the PS3, they’d at least subconsciously think the PS3 was more advanced.

Because it doesn’t have any understanding of the rules of chess or even an internal model of the game state, it just has the text of chess games in its training data and can reproduce the notation, but nothing to prevent it from making illegal moves, trying to move or capture pieces that don’t exist, incorrectly declaring check/checkmate, or any number of nonsensical things.

It took almost exactly 5 years from publication for that to be commonplace.