This is a narrative I've seen pushed. I have yet to see any meaningfully large segment of normal Americans "gloating." Here on FR, I see anger, sorrow, and resolve...but no cheering for the Taliban.
Do I believe the more knuckle-dragging parts of society cheer on the Taliban? Sure. Do I believe there are as many Antifa losers in the happy camp as there are Stormfront losers? Of course...they each share a love of control and authority and probably secretly wish their overlords were as "committed" as the Taliban, just like the people who slobber all over Putin.
Do I believe this "gloating" narrative is an attempt to smear classical liberals and anti-lockdown and pro-Trump people? Absofrickinlutely.
The are projecting, again.