I think you're right in a way Actually it goes back further than that to Reagan aiding the Taliban and other tribes when they were fighting the USSR. But neither Reagan nor Trump recognized them as the government of Afghanistan. It was more recognition as one of the 18 tribes of Afghanistan with the Taliban being the largest tribe and most influential.
Now if the Taliban take over the government, becomes the government, it seems rather silly to me to not recognize them as such. It will be fact. I'm of an opinion that it would be better to set up diplomatic relations with them, work for some cooperation between the U.S. and the new Taliban government in hopes the Taliban doesn't resort to their old ways when they were in charge before becoming a safe haven and training ground to terrorist groups like AQ, ISIS and others.
Simply ignoring them, not recognizing them, would push them back into their old habits much faster than if we did recognize them as the proper government of Afghanistan along with having relations with them. My two cents anyway.