I’ve never heard of anyone complain of having a coop or run too big. I’ve found out the hard way that a small coop or run leads to more behavioral problems, gives me less flexibility to deal with any problems that pop up, and I have to work harder. To me, the coop and run being a little larger than the absolute minimum you might be able to get away with makes my life easier. I’m OK with that.
Once you get adult chickens in there it will not look nearly that large. I suggest you install a droppings board to help you manage poop. That’s about not working harder. Once you get to your maximum number of hens you may find that managing the poop in that space could be an issue. A droppings board can really help you with that.
You should be OK with that size, but I would not want it to be any smaller. But I can be a bit lazy sometimes.