I feel like they are selling Boru/Sara mad hard. Why do you think that is? Mitsuki should be the last guy playing matchmaker. But even he has them pinned as a couple. I think this may be setting up plot devices for future developments.
Obviously. Sarada goal is to become a hokage which mean her role is to spread some love as she is more extrovert whereas Boruto act as an introvert as he is likely carrying burden on his shoulder. There is a real parallelism between the two following the premise of Naruto then their friendship forming into romantic relationship is bounded to happen. I think that's symbolic way to represent the Indra/Ashura unity.