Paint Ready Finish

I’ve recently had approx 2500 sq ft of drywall installed in a basement reno. The contract stated the drywall to be completed to “paint ready finish”. My painter is requesting additional fees since the new drywall wasn’t blended into existing drywall along the stairs that have a sand/plaster texture. Painter is stating paint ready should require only painting and drywallers are stating blending the finishes and any texturing isn’t part of a paint ready finish and actually the painters job. Can someone please confirm? Thanks