In my case, I was lucky. I had very little chest hair when I started HRT. That is partly the result of genetics, and partly the result of the same pre-natal hormone exposure that made me trans.
What little chest hair I did have, a few dozen hairs, has effectively disappeared. The only hairs I can find now are a couple of very fine gray hairs around my areolae. I have never shaved my chest.
Body hair does naturally diminish on HRT. Whether it goes away entirely depends on what you started with. I still have a bit of hair on my legs, but much less than when I started. I mostly don't worry about it, though I do sometimes shave it in summertime.