School access matters, but it is better thought of as a recruiting channel than as a strict ranking of candidate quality. Some universities and MBA programs have deeper relationships with MBB offices, more on-campus events, larger alumni networks, and more predictable interview pipelines.
Within the strongest target schools, the differences can be smaller than applicants assume. A candidate at one top program is not automatically advantaged over another simply because an internet ranking places the school a few spots higher.
The more important questions are whether the firms recruit actively at the school, which offices hire from it, how many students actually receive offers, and whether the program gives you access to strong preparation and alumni support.
If you are choosing between schools, use placement outcomes and fit with your broader goals rather than optimizing solely for a perceived MBB prestige hierarchy.