Well most of my friends who played DOS:2 was quite mad about this. Larian has local official social media account in my country and reposted related some fanarts, you guess what, people gather in the comment of the reposted paint, expressed their dissapointment about the closing slides, that's really awkward, especially when people are really care about their LIs. One of my friends-the one who recommend DOS:2 to me-is quite sad even now when we talked about that skeleton, and so do I, cause I don't know what did I do makes my LI leave me in the ending.
Seems that they make wonderful romantic storyline in BG:3, and quite proud about it, make it a selling point(from the interview by Lead writer,
https://youtu.be/qYD5HHKmVT8). That's insane if it goes the same way with DOS:2, you didn't miss anything, and sure the official resource didn't give any guarantee about the companion endings. I feel as anxious as you.
If there's any Larian staff reading this on the forum, please, be kindhearted. No more scums on Faerûn and no PC deserve a destined lonely life, give us more choice pls, that will make the forgotten realm warmer and brighter.
Sorry for my poor English.