Does this mean that Racket is now R7RS compatible?

You assuming Chez is R7RS compliant?

I thought I read somewhere that it was. Am I mistaken?

> As a superset of the language described in the Revised6 Report on the Algorithmic Language Scheme (R6RS), Chez Scheme supports all standard features of Scheme [...]

https://github.com/cisco/ChezScheme