Only things in a language that should be deprecated should be the things the normative body for that language deprecates in favor of other things offered by that language.
Abusing your position as a library author isn't deprecating anything.
Remember when the undici guys deprecated request.formData for _all_ serverside JS installs everywhere including bun, node, deno, because they felt it was unsafe? wonder how they're doing these days.
I just find it wonderfully weird that no process has been found to just handle powdery flammable things better, instead of adding stuff to it to make it less risky to handle it wrong.