Obviously this 1944 USA Supreme Court ruling is not being followed today. However, it was an important case the Society lost, and I'm sure the impact was felt for some time thereafter. It's a ruling most JWs and ex-JWs are not aware of today, and I'm certain the Society wishes to keep it that way.
I don't know when the 1944 ruling was challenged, if it ever was. The Society uses any loophole possible if profits from required door-to-door selling is at risk. Offering literature for a suggested "contribution" is the latest scheme to avoid paying taxes from the millions made each month using indentured servants (adults and children alike). The 1944 ruling must have been a bitter blow to the Society, on top of everything else that was going on during the Second World War.