What?! Rails has been announced as dead at the release of almost every new MVC framework. The last major proclamation was when Phoenix was the new hotness.
Search for "rails dead" and you'll find a whole genre of Rails eulogies ... and denials that it needs one.
All of the ones I’ve seen have been “dead” in the sense of “there is some new hotness that has replaced it for new projects” not “no one is still maintaining Rails”.
A new release contradicts the latter, not the former.
If dead means not the new hotness, then yes, Rails is dead. If it means the project has stopped releasing major features and improving the code base top to bottom, it isn't.