So? The NBER business cycle dating work covers back into the 19th century, even if some of it was done retrospectively. If anything, the fact that it applied it's methodology this way to times when there could not possibly have been any policy impact to its decisions just further undermines the idea that exceptions to the 2-consecutive-down-quarter rule are about current political convenience.

> And 1947 marked the first year the US produced a quarterly GDP report.

NBER was doing income and product reports before the government did, the government actually directly was motivated by NBER’s prior work in starting to do them.