Everything is a fair game during N-400 interview. Prior decisions have some weight, but do not mean automatic approval in future cases. Multiple interviews throughout immigration process at various stages are designed to catch errors or identify things that weren't checked previously by other officers.
I recently naturalized under 5 year rule.
My marriage is great, my 10 year GC was approved few years ago without interview. Despite of that, officer really tried getting more info about marriage, even though I applied at 5 year rule. Would my lawyer not be there, I'm sure we would have gone back almost a decade ago with me explaining how I met my wife, how and where we married etc etc. I brought all bonafide marriage evidence, thankfully didn't need it.
Be ready to talk about prior marriage. Be ready to talk about your entire immigration path.
Here's experience from my interview under 5 year rule: