On 23-05-2019 starting with 11:00 EEST ( 01:00 PDT/PST / 04:00 EDT/EST ) for 2 hours, we'll be updating Wordpress to the latest version 5.2 on all production instances. During this time, the wp-admin can become inaccessible for brief periods of time while the new version is applied. The public sites will not be affected and they will work normally. For any inquiries during this time don't hesitate to contact us at email@example.com
We recommend you to test this new version on your development instance, as they are in the process of being upgraded to the latest WP version at the time of this maintenance schedule. If you find any problems before the maintenance, please drop us an email at firstname.lastname@example.org
containing the Subject: "WP 5.2 upgrade problems"
More details about the new version can be found at https://wordpress.org/news/2019/05/jaco/
UPDATE: as WordPress 5.2.1. is out, the update will take place directly to this version. More details about this maintenance version can be found here:https://wordpress.org/news/2019/05/wordpress-5-2-1-maintenance-release/