I am very much wondering this too. I've used Pulumi and like it a lot, it has a great UX in general. But the ecosystem for Terraform is orders of magnitude bigger, e.g. searching for help on Terraform is going to give a lot more results than Pulumi. As someone who can dig into details, this is not a big deal and can use Pulumi on personal projects but cannot in good faith recommend it for team projects only because of the ability to find resources is more important then.

I don't know if the license change actually means providers will not be able to work with Pulumi, but if it does, it seems risky to use Pulumi even for personal projects if newer provider versions (i.e., versions that work with newer products released by the cloud provider) will not work with Pulumi, it's a dead end. And that's not to mention the useful providers that aren't cloud and completely community developed that will not have the resources to maintain two codebases in any case (I'm thinking of Sendgrid).

I looked at terraform-sdk license - it still seems to be MPL. I think this means that all providers can continue to be open and work with both platforms, it will be important for Pulumi to clarify this to prevent the death spiral. Given some negative feedback towards the Hashicorp blog post from Pulumi employees on this thread, I am somewhat skeptical of this since if everything is fine, then complaining will otherwise have a negative effect, that us users have to assume that Hashicorp is actually stomping them out. And if it's the case, sorry but in good faith to everyone else that may need to work on infrastructure I make, I will have to be complicit in the stomping.