This tier list is made by Dredrick, who plays in Champion ranks in RTA. Those not listed in there means they are not played often enough to be in there. However, the list is made for master/challenger players. This is what you would expect from those ranks.
You can check out his channel at -> https://www.twitch.tv/dredrick
The previous tier list can be seen here: https://epic7x.com/rta-tier-list-v1-3/
The point system is currently like this:
Most people will be in Bronze, so often times you will see pocket picks and some unique picks. Once you get to silver and higher, all the top tier picks will show up almost every time.