As this thread shows most kids at the time, including myself, never heard of Tiffany cards. Beckett was the preferred go to for kids at the time and Tiffany cards were left out of the price guide until the mid to late , 90s well after the last printed Tiffany set of 1991.
Even those kids that did hear about them through their LCS, the price was well out of their reach.
Sure, there may have been some kids somewhere that bought them or received them as a gift (most likely 1987-1989 as these had much higher print runs), but not enough to have any significant impact. A much more likely impact would be sets purchased by adult collects at the time who passed away or threw their collections away as the era became known as junk wax.
Up until recently, I had been tracking down as many sets numbers as I could. You can find the list of found sets on my website
www.tiffanycards.com