So the most rigorously concise answer to your laundering query is: fades. So the whole thing about holding off on washing is from the world of high end denim/ work wear. With raw and selvedge denim, the cotton is often dyed in the more traditional yarn-dyed method where the dye does not fully penetrate the yarns. Over time, the dye with chip or rub off, creating patterns of wear (fades), which will be distinct to your body and how you wear your clothes (e.g. elbows, crooks of the arm, even outlines of what you wear in your pockets every day). And the longer you go without washing it, the more distinct those fades will be, especially after the first wash. If you're interested in this rabbit hole, buzzwords include: selvedge denim, raw denim, unsanforized, honeycombs, whiskers, slub, nep. Carl Murawski has an excellent YT channel with vids on the topic. Have fun.
