@always happy:
The actual problem is in the way you phrased your question: “is there anything wrong?” Based on this terminology, you are going to receive a variety of answers from people who have different views of what the right thing to do is. Some people feel that not only is this not wrong, it is the responsible thing to do, and a boy who doesn’t go to school is doing something wrong by not taking steps to provide for his family. There are those who might say that yes, a yeshiva bochur going to college (even at night) is wrong, because college is no place for a yeshiva boy, and it is taking him away from his learning at this most important stage of his life…etc. All these responses also contribute to the relativity of what a “good shidduch” is. after all, “good” is an extremely relative term, and the point of reference of the responders is diverse, so only you can really answer what this means for you. Perhaps your query needs adjustment: what are the pros and cons of a learning boy going to school at night, and how will this impact his shidduch options; how does the yeshiva community view boys going to school at night; etc. These are valid questions to ask the klall, because it is not a matter of right/wrong, but of opinion, and people can describe their choice and how that worked (or didn’t work) for them.
This question will be personal to each individual and his life circumstances. It’s hard enough to make this decision as it is in “real” actual life, so when the question is posed hypothetically in a public forum, I am questioning if there is an actual answer.
Understand what I’m saying?