Do I need to increase the liquid amount when adding cheese to my scone recipe?
In general, I would expect this to work without adjustments.

The cheese is not actually a dry ingredient - as you say, it doesn't absorb moisture. If anything, it's slightly wet, in that as it melts in the oven, it will soak/meld into the scones a little. So if you had sufficient cheese, you might manage to turn things into a bit of a greasy mess. But in this kind of ratio, 50-100g of cheese and about 900g of other ingredients, that really doesn't seem like an issue.