How serverless adapt to new features (e.g. new resources and new resource properties) in CloudFormation?

According to the documentation, Serverless uses CloudFormation internally.

If Serverless use CloudFormation internally, We assume that even if new CloudFormation functions (e.g. new resources and new resource properties) are added, it can be handled without upgrading.
Is this assumption correct?

If the assumption is wrong, I have 2 questions.

(1) How many days should we wait for getting your support to use new features in serverless framework?
(2) Could you tell me one of actual cases that Servereless Framework requires version update to support new features in CloudFormation.