They forked the coin to be pure POS, the POW version is still running, but I doubt an exchange will list it as MACC-classic.
When did they forked the coin? So POW is still running but useless?
Around block 35000. And well, useless, depends how you look at it. The running POW chain is the first release. You can keep mining it, but coinexchange.io switched to the POS fork. Technically, if you get MACC-classic listed on some other exchange, it's not useless to mine.