Today - the Pulumi Azure provider is based on the upstream Terraform Azure Provider. Our goal is to be up to date within 48 hours of the upstream provider. The upstream Terraform Azure Provider is a little more inconsistent - but for most features is kept very up to date with new services and features in Azure.
Notably - for Kubernetes - we are today up to date within minutes/hours of new releases of the Kubernetes API (1.19 is releasing tomorrow!) because we have our own provider that is derived nearly completely from the Kubernetes OpenAPI specs (that is, we do not have a dependency on a Terraform Provider for Kubernetes).
We also have some exciting new work in this space which we'll be sharing more on in the coming months - stay tuned!