Spoilers:
I agree. There may be more than one entity and/or illusion at play onboard that're fooling everybody into thinking they're talking to a loved one who had survived, who told each of the party members not to tell everyone else that the loved one is alive during their reunion, like Connor told Garret the first time they met, considering everyone in the main cast is disappearing and then reappearing again all the time and claiming they got separated, lost, turned around, or went to investigate a noise.
I think I've figured out why Joseph and June were the first two victims out of everyone who made it on board the Arran. Neither of them had loved ones among the crew of the Arran.