I will add you. Welcome.
I think this is the article where we heard of it:
‘One Tree Hill’ Star Hilarie Burton Reveals Lucas Was Originally Supposed To End Up With Brooke (Interview)
I have the same opinion.
It was not easy for them to do scenes together, but they never showed it. Their chemistry was AMAZING and I was just more in love with them in S3. So sad that the writers had to end it probably because of C/S.