I know the team is working hard to get codegen updated to support 3.0 within the next couple of months.
It's a slow process moving over to 3.0, but people are doing it. In our experience, we see a lot of individuals converting to 3.0 when they currently aren't defining their APIs with Swagger 2.0 but are now looking to standardize on OAS. Swagger Inspector helps most with this process. SwaggerHub has an easy 2.0 to 3.0 converter for APIs already defined in 2.0.
It's a slow process moving over to 3.0, but people are doing it. In our experience, we see a lot of individuals converting to 3.0 when they currently aren't defining their APIs with Swagger 2.0 but are now looking to standardize on OAS. Swagger Inspector helps most with this process. SwaggerHub has an easy 2.0 to 3.0 converter for APIs already defined in 2.0.