Bacteria found to produce proteins that act like antifreeze

You don't need to be a bacteria to produce antifreeze. Even a frog can do it.

https://en.wikipedia.org/wiki/Moor_frog

Lots of antifreeze out there in the biology world. Most of them aren't useful because ethylene glycol is easy to produce and is quite superior (albeit super toxic) so nobody cares.

Also, the title is wrong. The bacteria is making proteins that produce antifreeze. The protein itself isn't the antifreeze or acting like an antifreeze. Otherwise it would be super wasteful metabolically but would actually make it an interesting evolution adaptation.