A leak on Weibo claims that the Galaxy S10 lineup will consist of 4 versions of the phone rather than the usual 2. One of these will be a 5G variant - with 12GB RAM. The Weibo poster also believes that the Huawei P30 Pro will have this spec.
https://www.notebookcheck.net/Samsung-Galaxy-S10-now-rumored-to-come-in-4-variants-one-of-which-will-have-12GB-of-RAM.346356.0.html
Actually 12GB could provide stability and redundancy. Currently I use a GCam port prone to frequent memory leaks, I have 6GB of RAM and the GCam causes slowdowns and lock-ups after a few snaps in low light, 12GB means it could leak plenty before I notice anything.