It looks like Samsung has a 120Hz display in the works
The Samsung Galaxy Note 9 now has a One UI 2.0 beta. The in-testing ROM in question updates the 2018 flagship phablet to Android 10 for those in the appropriate official software program. This would be good news in itself; however, it appears the new OS has yielded a further Easter egg for those interested in future premium devices from this OEM.
Ice Universe has posted screenshots he claims to have been sent from users on this beta that makes references to next-gen screen technology on Twitter. The 2 images in question are allegedly derived from the Korean- and Chinese-language versions of One UI 2.0 for the Galaxy Note 9. Nevertheless, the characters "60 Hz" are eminently apparent within the screens' contents - as are those for 120 Hz.
An English equivalent for the same pages, subsequently contributed by Jay Dabhi, appears to confirm the impression they make: the setting is one to set a display to 120Hz. Samsung already apparently has a marketing name for this option ("Best Display"), and advises the user to switch to it for a "smoother" screen experience.
Needless to say, the Galaxy Note 9 can't actually enact the new setting. Therefore, should it be genuine, it is obviously in development for a possible 2020 successor to this phone, or possibly to the Galaxy S10. This would make the S11 - a phone already linked to the Exynos 9830 processor, 8K recording with a 108MP image sensor and additional display upgrades - an exciting flagship indeed.