I don’t know about the ozone layer specifically, but reentry turns the satellite into danger dust – mostly metal oxides and burnt polymers. Ozone, being a very strong oxidizer, is the most likely to react with the hot debris, so it probably does damage the ozone layer, but I can’t quantify the damage, or the released pollutants.

When they say “burn up on reentry” they don’t mean disintegrate, they mean burn. It’s exactly like throwing thousands of home entertainment systems in a fire except that the pollution is in the upper atmosphere where normal pollution doesn’t reach.