I think that’s an interesting question and it’s hard to weigh the options.
Due to the current talent gap in the EA movement, I think it would make sense to encourage people who have quantitative expertise to transition towards a high-impact career, as those skills are (and continue to be) in high demand within the EA community. People could become less EA-aligned over the course of time working in a non-EA-aligned environment. Furthermore, I’m unsure whether a single senior leader could unlock the same potential in the financial industry. Also, there are opportunities to transition into an EA-aligned career path within the financial sector, e.g., working for the crypto hedge fund Lantern Ventures.
Even though it could be impactful to have “EA allies” working at mainstream companies, I think transitioning into a more EA-aligned career option could be the better option.
I also want to mention that I’m not too familiar with the financial industry, maybe you want to reach out to Meg Tong who is running EA Finance. I'm sure she has thought this through more profoundly :)