> First, it is unclear how to apply the LGPL’s statement about dynamic linking to a language like Racket, where macro expansion can copy code from libraries to applications, and where applications are typically bundled with the Racket runtime and libraries.

Linking exception, same as with GCC. Parts of GCC and GNU standard library make themselves into the produced binaries, but the license explicitly allows the resulting binaries to be licensed under any license the author wants.