All kinds of engineering majors go subs, as well as History/English/PoliSci/other majors, as long as they do well in required STEM courses. They all get a BS; all will get the training they need at nuke power school, prototype and sub school. They should major in what they enjoy and ensure STEM performance is strong.
Out of our sponsor family going subs, we have had aero, history, English, ocean, systems, mechanical, physics, chemistry - full range. What they had in common was strong STEM performance, interest and desire for sub mission, excellent conduct and performance/military aptitude grades. They also did well on the required oral interview.
The History major was in top 10% at nuke power school. The aero major was #2 at NPS, #1 at prototype, #1 at Sub School. The competition baseline zeroes out at the start of the nuke training pipeline. Everyone brings their brains, study habits, and backgrounds to a new set of challenges.