It would mean Pulumi has better coverage than CFN and terraform. Indeed as their blurb states, Pulumi would have 100% coverage.

But I'm skeptical.

afaict the aws terraform module tends to have 100% coverage. i've never found a resource that didn't work, or didn't already have some way to use. i was able to deploy eks when it was still in beta through terraform, while i think the cloudformation stuff for eks lagged behind like almost by a year.