Imo no not really. A levels are waaaaaaaaaaay more important. For example I only 4A's an A* and 4B's (I did the new gcses too for Eng and Maths). But I managed to get an offer from a medical school, an interview at another one too, as well as an offer for pharmacy at a Russel group uni.
Getting all A's and A*s isn't really needed - it does make applying so much ****ing easier though.
So in general. No not really, GCSES don't matter as long as you don't fail them. If you fail your gcses, your kinda ****ed tho...