I haven’t really followed the thread much (probably should have, as I may be repeating something someone else already mentioned), but I did read Popa’s question. The word “snuah” is not translated in this possuk as “hated,” but as “the lesser loved.” Yaakov didn’t hate Leah, he loved Rochel more. The idea that the Torah is teaching is that one wife should not be treated better than another, and if the less-loved one has the first male child, HER child is the bechor.
If she were truly “snuah” to him, i.e., he actually hated her, is he required to divorce her?