This is not the ‘general’ advice. Many schools have said to submit only if the score is at the median of last year’s admitted students (use enrolled stats if admitted stats are not available). Hence, many counselors are giving the same advice.
It’s not always clear cut, and there are exceptions, but often, a score in the 25%-50%ile does not strengthen an application, and in fact, may weaken it. Even if neutral, could make sense not to send it.
I agree that we just don’t know what is going to happen this year, with application volume by round, or test score submissions.