SERVICE IMPACT There will be some downtime during the maintenance window that can occur any time after the maintenance start is announced via the status site. Do not perform any large data imports or changes before your site is refreshed during the 24 hour maintenance window. Please communicate this information to all users with access to your Preview Sandbox.
Data and configuration will be refreshed to match what is in production and any integrations or 3rd party configurations will also be impacted unless you have opted out. If you are on a dedicated database, you have the option to opt out of the data and configuration refresh. Please do so in your production environment by following the instructions found here.
Please note that the 2605 Preview Release (code push) will occur on April 9th 11 AM PST for EU/AE regions and 11 PM PST for US/AP/CA.