If these annoy you I highly recommend buying a set if the Bevara clips at IKEA, or a similar product:

https://www.ikea.com/us/en/p/bevara-sealing-clip-set-of-30-m...

I highly recommend, just twist the bag 2 or three times and slap the end under the bread.

Also surprisingly handy at fixing your flip flops, or at least fixing them long enough to go to the store to get a new pair.

I shake my head disapprovingly at the use of twisty-ties to seal bread bags. We always keep bread clips around as the superior fastener.

Related question, would these be considered "fasteners", or some other thing entirely?

They are clearly fasteners, though this subtype is part of a class called in a general fashion “closures” (a rivet is an example of a fastener that is not a closure).

They have the bonus function of carrying expiration date and other manufacturing trace data.

And no, you cannot call these closures, unless you call them “closures”.

Bread clips are inferior to plain twist-ties, which are, in turn, inferior to the dual-wire "twist-ties" that can clamp down without twisting. I'm not sure what the proper name is for the last fastener as the lack of twisting makes the term twist-tie suspect.

I know the type you mean, with the dual wire ones. It's interesting that where I'm from, those are the standard bread clips, so the ones in the original article just look unusual to me. I think I saw a couple when I was in the US though.