I do not think we should be taking away any kisses from AA, hell from what I saw on the reddit post about him having a neck bite kiss then I am in support of them adding it as well. I would not mind that they repurposed his spawn kiss in the evil ending only if they had given him new kisses for UA.
Asking for his original kiss that people saw in a karlach origin but given him softer expressions, I think should be okay and a reasonable request. With that being said I truly want the kisses to be equal that would mean:
For AA he has: 1. new evil neck bite kiss that someone found files from on reddit 2. kneeling kiss 3. kiss that was in karlachs origin 4. kiss of him biting tav/durge lips
For UA he has: 1. kiss of him grabbing tav/durge ass 2. kiss of him holding their face 3. kiss from origin karlach but with less harsh expression 4. new kiss that was found in files
That to me would be very reasonable & would make the most sense so then people don't feel like one path gets more than the other. Oh and to add an endgame kiss that can be used for both AA/UA.
Edit: I also think it would be nice for him to have one kiss that is similar to UA in after his ascension because then it would show that Astarion is still himself even if he is a little rougher than before.