Not Apple related, but computer related indeed. Apple will probably want a stake in this.
This is something that the fab has to adopt in their process, first. Apple now has digital semiconductor design (with the purchase of PA Semi), but in no way has semiconductor fab.
Now, from the brief article, this can help with coming up with a fast and jitter-free clock - but that's one small, small part of making a faster chip. Graphene may have more uses than that, but until the boys and girl in the fabs at TSMC, Intel, UMC, IBM, etc. get it into their processes, it's just a curiosity.