I don't think that would, practically speaking, work.
If a Founder went to the planet right after WYLB, for instance, then they theoretically could transmit data back three years into the past that could change the course of the war.
Except...the Founders already lost the war, so either their information made no difference (predestination paradox), or they created an alternate timeline that has no bearing on them (multiverse).
Hell, maybe a Founder did go to the planet and they created the timeline in which the Founders lost the war.
Wait, I think I got that wrong...information broadcast from the planet is from three years earlier, information broadcast to the planet would be received from three years in the future... But that just means that if a Founder wanted to change the course of the war right after WYLB then they would have needed to have someone on the planet three years earlier to receive their transmission. Or more broadly, you would need to know three years ahead of time that you were going to want to send information into the past.