Absolutely !
Test the code and process first, and be sure to think of all the Murphyisms (things that could go wrong) you can and test for them.
But, I expect that he may not want to replace/copy all the members in the PDS.
I am assuming the PDS is on a mainframe. z/OS control of a PDS goes back farther than MVS. If I were in ISPF and manually edited a PDS member, what really happens is a new instance of the member is created and appended to the file. You have to run a compacting (compress?) procedure to clean up a PDS file to remove all the old "versions" of modified members. Because of this, I assume that when doing an "inplace" update of a member with SAS, the same thing will occur. The fact of FILE PDS(member) I believe will cause a new version of "member" to be created/appended to the PDS file.
It has been a few years since I used a mainframe, but I remember inherting a number of PDS's that had gotten huge, and while tech support was going to grow the allocation, I instead ran the compaction (compress?) and the files reduced in size by a huge amount (> 10x?, it's been a long time).