Chance me for UCI/UCSD/UCSB?

MAJOR: Computer Science
IGETC: Yes
Major Pre-Reqs: Will be missing 1-2 classes for UCSD and UCSB, in the clear for Irvine
GPA: 3.61, could drop to 3.48 after this semester depending on how I do
ECs: STEM Program at my CC, worked part-time

I am a California resident. I submitted a TAG to UCI and am currently taking Calculus based Physics, my critical thinking course, and the 2nd level of C++. Next semester I am expected to take the next Physics course of the series as well as Calculus 3 and Data Structures, do I stand a chance at these schools?

On a side note, I’ve heard horror stories of people submitting a TAG for Irvine, maintaining a GPA above 3.4, only to still get rejected in the end… why is this?