Definitely not. It began as indie rock. Alternative was the term major labels adopted post-Nevermind. Pearl Jam was alternative rock. They were never indie.
Maybe it's because of my age (GenX, born 1969), but the whole idea of "Indie" even being a definable genre of music doesn't make much sense to me. It began as "alternative rock," which just meant "rock music that doesn't sell much." That still seems about all it means.