Depends on your point of view. If you're a hard polytheist, like me, and view Gods and spirits as having some form of independant consciousness (though what for this could take and how it truly functions I don't pretend to guess), it should be possible for them to re-emerge and reveal themselves to new followers. This is borne out to a certain extent by reports of contact episodes involving Gods and beings that are down to a name and a job description in extant lore, but who yet present themselves as fully-formed personalities.
Of course, we could all just be barking mad.