The preseason is bringing a lot of changes. One of those are the two new drakes descending on the Rift, and Riot are allowing us to test them out extensively by doubling their spawn rates.
The only way to truly test out the changes to League of Legends is in a live game. Nothing can replace the authenticity of playing against real players, instead of bots or in a custom game.
But this is a time-consuming process, especially so if the changes we are testing are related to new drakes. So Riot is making the new drakes appear more often as the third drake in the preseason, granting the map changes and the drake soul, compared to the other four elemental drakes. This is to allow players to get adjusted to the new buffs, before season 12 starts.
"We're introducing two new dragons to Summoner's Rift, complete with new buffs, souls, and terrain effects. The selection rate of Chemtech Rift and Hextech Rift terrains will be temporarily doubled during patch 11.23 only so you can try out the new map changes and dragon souls more frequently during the preseason."
This will allow all of us to find out what exactly is the hierarchy of these drakes. What we mean by this is whether these new drakes will be a new could drake, that can be given to the enemy in favor of baron or some other objective, or an infernal drake that must be taken at all costs.