Eclipse seems to have deprecated the API which the Navigator View is based on in 2009 already and now schedules the view itself for removal as well:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=550379
Not sure what this means for the plugin, so asked that in the bug tracker. But other Eclipse-based projects and plugins seem to prepare:
Ping... In the easiest case, simply don't use that view anymore, but the default Project Explorer instead. It looks good enough to me.
I agree - could you examine it more closely and remove the offending view?