Bro is cooking and baking with this one. SanPud is literally endgame. The reason Sanji's memories were taken is because I think Sanji is a total 'wife guy' who once he has a girl, he locks in - kind of like Gaban when you think about it. Gaban doesn't want Ripley, the love of his life, knowing about his previous escapades. He values and treasures that relationship, and I think Sanji will do the same.
If Sanji remembered the kiss it would ruin what Oda thinks is a funny gag, as Sanji would stay loyal to Pudding.
I look forward to their epilogue, and, of course, Sanji being the knight in shining armour, the prince who saves her from the BB pirates. It will be peak.