Well, their owner is probably cash-strapped because he had to borrow money in order to buy the franchise, but they're not in that kind of financial trouble.
They released Dee Brown for the same reason that the Bucks released Croshere or the Clippers released Fred Jones or the Heat released Livingston: they had non-guaranteed contracts and all contracts become guaranteed for the rest of the season as of January 10th. So yeah, it's somewhat for financial reasons (teams won't say that the player sucks anyway), but not exactly because they're in such financial trouble they need to make radical moves to diminish the payroll.