Word request: what's a startup-like synonym for the word "grapevine"
Solution 1:
An appropriate verb for this would be to say something like the following:
I planted a rumour.
From Merriam-Webster:
1 a : to put or set in the ground for growth
// plant seeds
1 b : to set or sow with seeds or plants
This not only follows the grapevine analogy, but implies that you started the rumour, and that you are also in on it—as well as possibly tending it after the fact so that it will grow appropriately.