Last year, Sidwell contacted us to tell us a day for our child to come in for the test and group activity - I don't think our child had a separate interview as part of that....but maybe. Our family interview was separate and scheduled via Ravenna by us.
If your child did test via Zoom - I'd contact admissions and ask about whether there is a child interview. I wouldn't think the interview portion depends on the assessment of the test first.