You can definitely go ahead and make this transfer if you like. The soil you transfer into should be quite similar to what they are in now. If you intend on transferring them to a very nutrient rich soil you should dig a hole in the pot bigger than your cup and fill that hole with the soil that the plant is currently in so it has a bit of buffer time. I like to do 2 transplants, cup to a 1 gallon of half strength nutrient soil and then 1 gallon to 5 gallon of full strength nutrient soil. I like this because they typically show me sex while they are still in the 1 gallon pots. This means I don't have to waste time and energy transferring males into 5 gallon pots only to have to pull them out again.