We know where he heard it.

Ooo I bet you're wonderin' how I knew
'Bout your plans to make me blue
With some other Patterson that you knew before
Some other Rosenbaum who'll invite you to the fifth floor
You should have told me yourself
But I found out from someone else
I heard it through the grapevine
How much longer would leronlimab be mine
I heard it through the grapevine
And I'm just about to lose my Cytodyn
Honey, honey yeah