I'm glad you're asking because I've seen it too and don't get it either. I assumed initially it was alpha as a typo, then I Googled it and got even more confused.

I think this is an interesting thing that will happen once the rate of change slows down a little bit - imagine a world where there's more or less a couple base models and everyone trains on top of them, and the bitter lesson is defunct just via sheer physics (maybe we have the best models we can physically run in reasonable energy density substrates, or something), then it becomes "your personal model" with your overlay, training, or feedback on top.