I'm going to chime in to disagree strongly with this. I've seen and worked with lots of non-CS PhDs in data science who have been terrific. It's pretty common too—there's even the Insight program that trains PhDs to go into data science [1]. I don't think it will be seen as a downside and will instead show that you know how to do research and solve problems.
Anecdotal, but I’ve worked with dozens of PhD data scientists, and not one of them had a CS PhD. The most common one I see is physics, followed by math. (And I don’t work in a physics-related field.)
[1] https://insightfellows.com/data-science