well naruto's and hinata's obviously. the thing about sakura's abilities is almost anybody has the potential to learn it. sure shizune said she couldn't do the byakugo seal, but compared to who we are talking about here, she is fodder and shouldn't be used as a barometer. but in the case of hinata and naruto's child you get the potential for greatness. their child would be a part of the hyuuga clan and thus gain access to all their techs as he would be main branch member. so anything the hyuuga have shown is a possibility for their child to learn. added with the childs uzumaki lineage, also having a father who is the transmigrant of ashura, will give this kid the ability to take these jutsu to a new level. most likely would be able to use sage mode and have added strength because the father is a jin with chakra from every bijuu. their child potential is almost limitless. if this kid inherits the task of being the meeting place for the bijuu in the future, he/she would be a more badass kaguya.
