I was accepted (yay!) but unfortunately I was not accepted into my chosen major (computer science). I’m kinda upset about it, but was wondering the chances of an internal transfer into the College of Engineering and back into my major. The truth is if its something thats fairly unlikely even if I get very good grades in the required courses, the school is off the table completely. Any help is appreciated!
Short answer: It’s quite difficult. You need a high GPA (and you will get in if you hit the GPA and grades required). But most hopefuls don’t succeed. About 50 succeed in transferring in each year. Don’t overestimate your ability.
Transferring in to some of the CS+X majors still is quite doable (just need a 3.2 GPA), but they may raise the requirements for those in the future as well, so if you have guaranteed admits to other at least half-decent CS programs, I would say DGS would be too risky a choice if I was in your shoes.
Oh man, well thanks for the information anyways. I am still waiting for a lot of other schools, but I’m relieved to know that if I hit the gpa and other requirements I have a good shot. I mean at other schools like University of Washington, only 40% of CS applicants who meet or exceed 
the requirements get in.
Well, the requirements for transferring in to CS at UIUC are high. Maybe a quarter of the class gets A- or above in those 2 required CS classes*? (I’m guessing here; could be a higher percentage). Which is why only about 50 manage to transfer in each year even though many more want/try to.
*That one CS Prof on Reddit did say that even the CS faculty won’t deny transfer applicants who meet those requirements (even though UIUC CS is really full with students now) because they would be in the top quarter of the current CS students.