So, I (an early career researcher) have an article submitted to a journal in Political Science. In the article, I use several interviews with very specific and very busy people from my related field. However, after I submitted the article, one participant-to-be got back in touch and said they have time now and we can conduct the interview. I did that. That participant gave some nice quotes and basically confirmed my research outcomes alongside others. Now, the amount of interviews in the paper is on the lower side of the spectrum and I want to include the last one as well.
The question is: Is it weird if I add another interview in the revision process to the paper? So, for example, it will go from six to seven interviews. I will, of course, explain what happened in the response letter as well (late response; it was in line with what the other interviewees offered; if there were something abruptly wrong, I would have pulled the paper anyway).
So is it acceptable to add more supporting empirical data at this point? Again, analysis does not change, premise does not change, etc.