That seems to be the case currently, but it would still be possible that Human players would potentially be in the other ship that's being interacted with. As I understand it, a player status can be on or offline, Ironman or not, then grouped in a sort of cascading set of availability for interaction.
My current understanding (as it makes most logical sense):
Modes:
- Offline (solo)
- Online (solo/group/all)
Both modes can't mix - offline you can call your commander whatever you want; online you are bound by FD's rules.
Game Type:
- Normal
- Ironman
Not affected by mode - it's simply a ruleset you adhere to. When online the different game types are segregated by grouping.
To walk about in another players ship then you would both need to be playing online & the same game type.