As a product manager, you will be expected to know quite a few different areas of knowledge. Not only are you required to become a domain expert in the product that you’ll own, but you’ll also need to understand the industry within which you work.
While most companies have some sort of on-boarding process for new hires, in my experience, I’ve found that interviewers appreciate when candidates are already knowledgeable about the role, the company, and the industry.
Candidates who conduct research before the interview are likely to be more successful, because they remove the burden from the interviewer in needing to explain their company and industry. The interviewer can then spend more time in better understanding the candidate’s fit for the role.