They represent fast forwarded time. Those locations start after the family meeting has been called.
Yeap. The chevron arrows represents the starting location but after the family meeting. So it skips a bit of time and would mean that the private investigator is already inside the mansion.
It’s also good if you haven’t done the Another Death in the Family challenge, and you don’t want to wait for too long.
In these selection menus you can press F to see some details. For the starting locations it’ll be a short text like “Agent 47 has infiltrated X by posing as Y and will start the mission in room Z”.
Amazing how i did not see that