I wasn't around for some time but I've heard someone found male dialogue for Cullen's romance and some dev confirmed he was initially supposed to be bisexual.
Is that true? Because there was also some dialogue recorded by male PC's voice actor for Sera's romance...
I happened to catch this, and I know the answer: no, it was never intended.
As a quirk of the way they do the recording, a lot of the planning and writing is occurring simultaneously. Booking voice actors late in the process is more expensive than simply having them record extra dialogue in existing bookings, so they have them record any currently-written dialogue for both genders, since the people in the studio don't know what has been planned, yet.
Basically, all the characters have dialogue recorded for both genders, and some of the files ended up in the game (extraneous stuff that wasn't entirely removed is left behind in virtually every video game made, nowadays.)
Edit: And this was confirmed by a dev, although I've forgotten which one.