Deston will be added to the common map pool in the next update
In the next major update number 19.1, the developers of PUBG: BATTLEGROUNDS will remove Deston map from the standalone queue and add it to the general map pool instead of Sanhok. This information was revealed via PUBG Support Service Twitter account:
[PC/Console] In Update 19.1, Deston will be removed from the featured queue and will be added to the random map pool by replacing Sanhok. This will occur for the regions (NA, EU, SA, OC, RU).
Thus, the following map will be in the general pool: Erangel, Miramar, Taego, Haven, Deston. At the same time, Deston map will appear in 40% of total cases, while the rest maps will have a 15% chance.