RestClient support in #36213 was followed by JDK HttpClient and Jetty client support in ClientHttpRequestFactories, #36118 and #36116. ReactorClientHttpRequestFactory was added soon after in Spring Framework, but there is no corresponding support in ClientHttpRequestFactories as of yet.
Note that ReactorClientHttpRequestFactory was called ReactorNettyClientRequestFactory in 6.1, but was recently renamed in https://github.com/spring-projects/spring-framework/commit/042346aa6a33fa5237ec847049cc252d0edc3637. In case you wonder why it's marked with @since 6.2.
Comment From: spencergibb
I wonder, if like the jdk http client, this should be opt-in by default in a minor. https://github.com/spring-cloud/spring-cloud-gateway/issues/3562
Comment From: philwebb
Reopening to consider if we should make this opt-in (similar to jdk http client)
Comment From: spencergibb
One backward incompatibility was not sending the body on a DELETE.
Comment From: philwebb
We're going to keep it as a default, but #36266 will make it easier to change.