For a friend.
OK first I am a seasonal tax preparer with you know who. No it is not standard practice to fail to include any and all schedules and forms. All schedules are a required part of the tax return. On the other hand, you said it was a ‘paper return’ which could mean a coffee spill or something at the IRS.
At this point with only a polite IRS request letter, I’d not be panicked and would get a clean copy from the CPA, verify that it matches MY record and mail it pronto!
Best regards.
IF the CPA sent the return to the IRS, the CPA is responsible for the Schedule A.
Have the CPA attend to this matter - that is what your FRiend paid the CPA to do.