Does Cal Poly SLO send its admissions acceptances all at once?

A huge wave of students was accepted over a week ago. My portal still says “no determination has been made.” Do they send more acceptances in waves, or is that it? Have any bio majors been admitted (stats?)?
Bonus question: Is biology a particularly hard major to get into at SLO, or is it on the easier side as most apply for majors like engineering?

Yes many are already admitted and I’m wailtlisted for that major. (4.08, 1990 sat, instate, lots ECs. There’s been a few sparse acceptances but nothing like a few weeks ago. Biology is extremely competitive, with 15-20 percent getting admitted.