The new update for the OnePlus 6 and 6T comes with a couple of features from the OnePlus 7 lineup. So, you can now have a feel of the OnePlus 7 Pro on your OnePlus 6 and 6T.
One of the features that are now available to the OnePlus 6 and 6T is the Fnatic Mode, found in the Gaming Mode. It is available along with Zen Mode and the so-called DC dimming feature that eliminates PWM.
Also, according to the changelog, OnePlus has optimised the Pocket Mode further. You now also have Quick Reply in landscape.
Additionally in the new update, OnePlus fixed an issue with apps failing to respond.
Users of the OnePlus 6 and OnePlus 6T will not all get the update at the same time. The company is pushing it out gradually, so it may take some time before you get it on your device.