Our experience with early July calls varied from college to college. IMO the important thing is for your son to be prepared to ask specific questions, take notes, and to never give a verbal commitment to anyone without having the offer, in detailed, for your review.
We talk about how important the right “fit” is, and this is really critical IMO. To make this important decision, you need to do your research before hand on the schools of interest: learn about their baseball programs, their coaching backgrounds & tenure, the school’s academic record and majors offered, and where possible take a visit to the campus and surrounding area, all before the recruiting season starts.
During those first calls it is usually a fishing expedition to level-set the interest between both parties. We did not experience a call where there was an offer given during the first communication. But to answer your original question, yes, you should have the complete offer provided, baseball and/or academic $$$’s, before your son makes a verbal commitment.