As much of a non-answer as this might seem, it will really come down to the people in your team and your new management which you won't really find out until the interviews and more realistically only when you're actually working with the new team.

If you have solid team members who are secure in what they know and their position they'll appreciate your broad(er) skillset and will want to work with you and it will be a non-issue. If anything they'll respect you tried something "beyond" what a normal senior engineer might do or get to do.

If you have one or more people who are insecure or "not an A-player" they'll likely view you as a threat to their career progression and you'll have to be cautious around these people.

A good / great manager wants people of diverse backgrounds and experiences, a mediocre manager might feel threatened by you because your insight might challenge his authority or the concept of it.

If you're interviewing with a team they'll likely know your background, but if it doesn't come up I wouldn't go out of my way to discuss your CTO role, just stick to the technology parts you've worked with.