Remember that sometimes promotional things like moving posters and what not do not necessarily reflect a plot point of the show itself (for example, there was a series of motion posters for Defenders with each of the heroes in one of the other heroes home turf - Luke was in Fogwell's gym, Danny outside Harlem's Paradise, Jessica in Colleen's dojo and I think Matt at Rand tower - even though within the season of Defenders itself those characters never went to those locations).
It's a little promo to tease us and get us excited. It doesn't necessarily mean S3 has him being listed as missing (does that make sense?)