Got In to UCSD but as Undeclared, told CSE unlikely, what to do?

My son got in to UCSD, UCI, and UCSC. UCI and UCSC accepted him as a Computer Engineering major. UCSD (his top choice) took him as undeclared, and I was just told very tersely by an admissions officer, his chances of getting into that major is very slim, now or later. Do we give up on UCSD? It seems an obvious, “Yes” but it is the highest ranked school he was accepted to, and he may find he wanted to do something differently as a major anyway… but if Computer Engineering really is his thing we may have to transfer him out to get that… oh me. Any ideas? He really is a well spoken kid, I think he would impress the powers that be if he got a toe in the door.

UCSC’s relative proximity to Silicon Valley computer companies can be helpful.

UCSD’s CSE major admission for undeclared students is described at http://www.cse.ucsd.edu/ImpactedMajor