The important issue is that it is STILL a 3g plant. If you put it in a 10g pot, a 20g pot, a 1000g pot, it is still a 3g plant. When it becomes a 10g or a 20g plant, then the watering requirements will change accordingly. But for now, it has the same amount of roots mass, the same amount of rootball, and drinks from the same amount of soil as it was before repotting. It doesn't matter how much wet potting soil is in the pot, the plant only has access tot he moisture that is in it's rootzone, which hasn't changed.
After that, it matters what the difference is between the potting soil that it had when it was a 3g plant, and the new potting soil. For instance, if the plant was in a water-holding medium, and the new soil is faster draining, you will feel the new soil and think it needs water. So you add water. But the plant is still seeing the the water-holding medium, which gets more overwatered each time you water, trying to make the fast-draining mix wet. Eventually you will drown the plants.