Yes, we’re not far away from launching JUCE 6 now.
When JUCE 6 is released we will be focused on building JUCE 6 features. JUCE 5 will not be updated to remain compatible with the latest versions of operating systems or other libraries and frameworks. If there is a particularly critical bug, that we don’t already know about, that renders JUCE 5 unusable on the current set of supported deployment targets then we can grant special permission for JUCE 5 users to apply the corresponding fix from a JUCE 6 commit. This will be the exception, rather than the rule.
We are not planning to do a last JUCE 5 release before JUCE 6, but we will be merging the develop branch into master beforehand. This means that there will be a JUCE 5 master branch commit with all the recent fixes available.