If you can get a job in that industry now, then YES! You absolutely should do what you like and let yourself shine there.
I think it will positively reflect on your application. However, many applicants find it hard to break out of their industry mold and switch roles. If you can switch roles/jobs/companies and focus on finance/what you like and see yourself at, it will be helpful across the board. It may also switch/change how you look at your MBA plans. You may choose to do a PT program for example (which is ill-suited for career changers) since you won't need to do a career change at that point and be able to avoid the opportunity costs and potentially excel within the same Finance/Asset management company.
The answer is get that job now.
P.S. Admissions love people with character, goals, and passion. Your choice and decision reflect all of those.
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