new hip hop

I have a question. When did any hip hop between 2000 and 2005 become old school? I think people have gotten it twisted these past few years. Now I'm a true believer of instant classic's but to call that era old school is ridiculous. Lately there has been a new wave of cats that are quick to throw the word old around. To me old school is run dmc, fat boys, and ll cool j. If you are calling mos def, talib, common, roots , slum village, j dilla, or anything dope from that era old school you're sleeping. I know that the kids now are a lot younger these days so here's a tip. Don't ever argue hip hop with a vet because you will get a lesson. Know your history