No more AWS Builders program?

Just went to the page for AWS Builders, the program that AWS has for startups to get $1,000 in free credits and got the following:

> We're sorry, the AWS Activate Builders package is no longer available.

> Check out the AWS Free Tier to gain free, hands-on experience with the AWS platform, products, and services.

> Already working with an accelerator, incubator, seed or VC fund? We have a Portfolio package for participating organizations. Ask your program director how to apply.

Any thoughts on why AWS would stop this program?