IBM has kept researching in Albany. They license manufacturing technology to other parties even if they gave up trying to build their own fabrication facilities a decade ago.
"Out of nowhere" would be a stretch. IBM may not have mass-market volume anymore but they kept up the production chain to build mainframes (and I would guess other "specialty" products) for institutional customers.
IBM has been publicly working toward 2nm since at least 2021, though, so it doesn't seem like it's coming from nowhere. Unless this is a completely different 2nm development, here's a presser about it from 2021, titled "Introducing the world's first 2 nm node chip" (https://research.ibm.com/blog/2-nm-chip)
Unless it has great yields with 0 issues, there's always things to learn from. It's also possible the IBM process isn't what it seems and there's more to it.
