Well, I can't believe this game is so popular on Steam, so many people are playing it, but almost noone has encountered similar issues and nobody has checked the info from this wiki yet
There are tons of ways to miss companions, noteably Shadowheart. In one of my my early access playthroughs, I did nothing unusual, yet she was not lying on the beach. She made it into the grove on her own. Lae'Zel, Astarion and Gale may be missed if you don't know they exist.
This is not the only game following this logic. I originally killed Zevran in DA:O because I thought he was lying. Lesson learned: ALWAYS check how and when to recruit companions in role-playing games. If you don't want there to be consequences, you need to be proactive in avoiding them. Furthermore:
even if you recruit some companions, that doesn't mean they won't leave if you mess up later on. It's genuinely good to know to which locations to bring a couple of them, such as Shadowheart! Your problem was also NOT the only time you'll get locked out of content because you took too long! This will happen regularly to the unwary!
