Quote from SirBrucePrice is a far greater determinant than "has it been reprinted recently". However, inasmuch as Mindslaver's reprint driven down the price, I would doubt it would be in Modern Masters. Remember, MM is about reprinting Modern Staples that are in high demand and limited supply resulting in a high price. There are plenty of Mindslaver's now.
There's no way the whole set is just valuable reprints though, and I wouldn't be surprised to see a bunch of cheapo rares that are fun in limited as well as under a dollar casual favorites. Mindslaver totally fits that.