Most masters choose to let go of the physical bodies, yet will appear when needed.
In The Autobiography of a Yogi, Paramhamsa Yogandaa speaks several time of his Guru Sri Yukteswar visiting him after Yukteswar had left the physical body.
And, i guess after 800 years or so Noah decided to leave his physical body.
One thing to real-eyes is that Yes & No are relative only in duality, which is not real reality (Unity). The mind is part of duality, so cannot compute non-logical answers. This is where the choice of deciding to believe in something (for now), or not, comes in. And remaining open to all possibilities.
RE: Ecency waves Feb 07