WordPress 5.0 “Bebo” was released on December the 6th. Since Gutenberg will be included in the new release, we decided for safety's sake, to defer the mass upgrade for the holiday season.
The mass upgrade to 5.0.3 is scheduled for the 29th of January, 2019.
Starting from the 15th of January, 2019, all new WordPress installations will be provisioned with 5.0.3.
If you would like to defer the upgrade to 5.0.3 for a few days, in order to complete your testing, open a support request.