It's kind of bizarre to think of the Final Four on cable rather than good ol'/stupid ol' CBS, but next year, the semifinals will be on TBS and the days of watching the whole thing for free are long gone.
That'll teach you cord cutters!
For broadcasters, with an increasingly fractured audience, big sporting events represent an increasingly rare chance to reach a mass audience (and to sell ads at lucrative rates).
The rest of us will just have to make a decision: keep the service or watch it somewhere else.