The chart shows safety altitude north of DIXIR as 7100. The clearance given descent according to procedure. No matter from where you come to DIXIR procedure doesn't permit descent below 7500 before DIXIR. The ATC waived of lateral procedure asked to maintain the vertical. I don't see any problem. If in doubt ATC should have been asked about descent below 75 before DIXIR.
https://www.google.com/url?sa=t&sour...dnWxTl57JT2idb