I don't read it as conflating, they just say these are all harmful, not that they are equally harmful. A hangnail is harmful and a car crash is harmful, I try to avoid both. I'm less put out by a hangnail and I go to great lengths to avoid a car crash.
Any list like this should be read as: "you are causing harm somewhere between a paper cut and a gunshot wound, you may not realize it. Be advised you might be causing that harm, in case knowing that would cause you to take a different course of action"
Surely it matters the extent of the harm, though? If I'm doing home wiring, it is not at all helpful to know "this could result in a slight tingle or kill you and burn your house down."
Ambiguity means I can wave off your complaints because clearly what you're complaining about is a hangnail. Ambiguity means I can punish you brutally, because how dare you not take my car crash seriously.
Stairs are really hard for people in a wheelchair, signage is really hard for someone blind, and fire alarms are really hard for someone deaf. Missing any of those ADA adaptions is more harmful to one group than another.
Harm can vary based on the person, so doing something "harmful" is person dependent. The goal is to recognize the harmful history of language when choosing words, because, thankfully all spoken words are newly spoken, so you can pick fresh each time.
In a huge portion of these cases the only harmful history is in the imagination of the author. "Tarball"? "Red team"? "Submit"? "White paper"?
All of these have very clear etymologies that don't have any offensive history whatsoever. The idea that we should avoid any term that uses the words "white", "black", "red", or "yellow" on the grounds that they once were used in some contexts to refer to people is absurd.
Any list like this should be read as: "you are causing harm somewhere between a paper cut and a gunshot wound, you may not realize it. Be advised you might be causing that harm, in case knowing that would cause you to take a different course of action"