<p>It’s very very rare to get your admission rescinded: they picked you because they want you and they’re too confident in their process to change their decisions willy-nilly. The only case I’ve heard is a kid who failed all his classes he didn’t need to graduate. That being said, don’t do anything stupid: you worked hard for four years, you can wait a few months until summer to let loose.</p>
<p>I doubt Stanford will care about your expulsion from the team. However, if it worries you, just email them and say exactly what you said here, with the same sincerity and contrition. Like lerkerman said, its certainly better for you to tell them than for anyone else to.</p>