Figured it out... well made it past that first error. You need to update the pulumi-tfgen and resources file and provide the provider options.

func main() {
	// Modify the path to point to the new provider
	rkeProvider := rke.Provider()
	rkeProvider.Repository = "<https://github.com/rancher/terraform-provider-rke>"
	rkeProvider.GitHubOrg = "rancher"
	tfgen.Main("rke", version.Version, rkeProvider)
}