You’ve just “gotten in” to the #1 public university in the entire United States of America. Pretty soon, obnoxious people in your life are going to start talking about imposter syndrome, and telling you that you shouldn’t feel out of place or like you aren’t meant to be among the UCLA cohort. Normally, that’s fine advice. Just not in your case. You DON’T belong here.
The Admissions Office intern who isn’t paid to send out 125,000 rejections fell asleep somewhere around “we regret to inform you” number 110,439 and accidentally fell onto the keyboard. Chaos ensued, and you were sent the wrong email.
Maybe they’ll realize their mistake and rectify it; maybe they won’t. I guess you’ll just have to stay awake every night from now until Fall Quarter starts seized with crippling anxiety, wondering if you’ll wake up tomorrow to a new email rescinding your admission. Best of luck!