Good question. I didn’t actually know, so I checked. It’s an actual gameplay affecting bug. I even timed it to make sure. It also affects the numbers on the production overview showing I’m now under producing, where before I was producing enough.
I ran an experiment for this. I filled fertilizer factory storage and connected the fertilizer factories simultaneously to vegetable farms. I clicked the first trucks to come out out. The screenshots are all during the same pause.
From the test, moving the buildings that should benefit from the effect will have their effect restored.
So no idea if loading a save will reaply it (but kinda doubt it will), since I have no boosting buildings right now to test it myself.