AWS Solutions Architect Associate Certification Course.
Section NAT GW
Wrong Statement - NAT GW requires Internet GW.
See the blog (Posted on: Jun 10, 2021)
why courses are not up to date.
I don’t think that you understood the AWS statement correctly. It says in the second sentence:
Internet Gateway is required to provide internet access to the NAT Gateway
For the purpose of SAA certification, NAT gateways are only to provide private subnet access to the internet.
The other use cases described in the document are advanced uses and would only be required knowledge for the Networking Specialty cert, which is a very advanced level, and possibly the Solutions Architect Professional cert.