some people just use their resources more efficiently than others. it is up to you to change the rotors or not, but we can expect that if they op is asking that they have concerns about cost (otherwise just do it).

assuming if they were in spec now and that they will not be later is just fear mongering. all we can do is provide rational and factual information to the op and let them make their own decisions.

if you have that much cash to burn, then why not change the rotors/pads with the oil? if we are assuming that BMW specs mean little to nothing and cost is not a factor, then that makes perfect sense from a cost doesn't matter point of view.

then again, if you really wanted to spread fear, you could tell the op to buy a new car every couple of years. that would match the cost doesn't matter argument perfectly since it is the most expensive thing to do!

then again, you would be in E70 forum and not the E53 one. clearly cost matters to you, so match your advice with your actions...