Here is a quote from my Social Security Statement dated 7/15/1998 under the heading Disability Benefits:

"If you become disabled right now, you need 22 credits to qualify for benefits. You have to earn 20 of these credits in the last 10 years. Your record shows you do not have enough credits in the 10-year period.

Because you do not meet both parts of the disability credits requirement right now, we are not giving you a benefit estimate. If you work in the future and earn enough credits to qualify, we will give you a benefit estimate then"

Didn't read the rest of mine, but this one Statement did spell out the disability requirement pretty well. I doubt it is an anomaly.