Sharing tech can also spawn new missions about people being very unhappy with your decision and trying to smear your organization. You have to take them down, preferably with non-lethal measures, but the protestors are as what you expect from RL. Certain enemy factions also may starting use some of said "shared tech" due the black market taking advantage of the situation.
IMO it is worth doing it, if only because there's no downside besides extra missions and a score penalty. I hope that in the future the decision to share tech with shady corporations becomes its own story arc in this mod, or something like that.
Funnily enough that's what you did in classic XCOM and Nu-XCOM, selling alien tech to third shady parties. In the "modern" XCOM, you even receive messages of places like Russia repurposing the alien tech you sold them for their police forces.