Nta but I think the size and style of locs makes a difference. Smaller locs that are kept neatly and styled for lolita look fine (they're similar looking to braids and twists at that point which are fine if you style them cutely like with neat updos, pigtails, down with nice face framing pieces, etc.) The girl with the dyed locs was wearing fairy kei or whatever anyway and had very messy locs and dye job which were both not maintained. It really varies based on the person and what their specific hair looks like.
Also side note: any black lolitas or jfashion wearers who get their hair braided often and aren't afraid of undercuts or some parts being short, highly recommend looking at Haruka Kurebayashi's videos of getting her hair done. She often does very cute colorful braids worn in pigtails a lot and with her bangs left out and the "kitchen" area of her hair shaved short with designs cut and dyed into it. I just love her in general for her cute and fun hair adventures and seemingly genuine appreciation for braided styles that aren't trying to be a caricature of black people or stereotypes but simply taking something cool that we have and doing something she likes with it without pretending she invented it like some famous people have in the west.