After having this annoying rattle coming from the back and having both myself and the wifey sit in the back to hear the noise to figure what it was...she must have better ears, she figured out that holding the hatch tight from the inside made the sound go away but once letting go, it came back. Quick search and found this post...after several attempts to knock it back with no luck, I ended just flipping it around...nice and quiet now.
Replaced actuator/latch assembly. $52 off Amazon and 20 minutes, problem solved:
https://www.toyota-4runner.org/3832196-post50442.html