The current module name spring-web-reactive is a bit of a misnomer because it does not contain all "reactive, web" functionality as its name advertises. The low level "reactive, web" infrastructure for HTTP runtimes and Reactive Streams is in spring-web. The higher level, generic web framework support comparable to the Servlet API is also in spring-web.
The situation mirrors the spring-webmvc module which contains the Spring MVC framework but also builds on a lot of infrastructure in the general spring-web module. We need a similar, distinct name for the reactive web endpoint framework.
Note also that the module name change does not have to impact the package structure. In other words just like Spring MVC actually lives in org.springframework.web.servlet while its module name is spring-webmvc, the top level package in the spring-web-reactive module can remain org.springframework.web.reactive while the module name is changed.