TNA releases a “I Hate Tessa” shirt.

This is just good business, like how sometimes booths get set up at protests/sporting events that sell cheap knockoffs of certain teams shirts or flags to toss in the bonfire as you tailgate and talk shit about the people you hate.

I'd argue it's likely TNA is using a print to order system like AEW does/did at the start so if nobody buys them they aren't out a lot of money.

Instead of releasing I hate Tessa shirts they should just release Tessa herself.

"Show your hate for Tessa Blanchard by wearing her face and logo on your body."

~TNA, probably