This question has been raised on pprune before by someone far better placed than me....I can't find the thread..
...but, just to re-cap the gist of what was said, the in-depth Airbus related questions are only asked of applicants who are already 'typed' on the Bus. You couldn't reasonably expect anything else really.
That having been said it would not be entirely unreasonable for an interviewer to ask in-depth questions about the type you fly at the moment..after all the question is only to probe your generic ability to understand and explain aircraft systems - be prepared!
