Many of these universities have vast investment funds. Expanding would indeed allow them to provide more education, but that does not appear to be their goal.
Expanding need-blind isn't the same as overall expansion.
Many universities have adopted need-blind admissions (not including donor admits), eliminated or reduced student loans, and/or expanded undergraduate admissions - all efforts that support economic diversity.
Stanford (for example) implemented need-blind for domestic student admissions (but still not international), and largely eliminated (or at least reduced) undergraduate student loans. Undergraduate class size seems to have expanded from ~6500 (?) in 1983 to ~7500 today, and may continue to expand slightly:
However, it's worth noting that Stanford acceptance was above 25% for the class of 1979 (vs. 3.6% for the class of 2029.) Application growth has drastically outpaced admissions and class growth.
