Where can we find what will be included in AEM 6.5 Service Pack 1 scheduled for release Jun 27, 2019?
There is a roadmap for all the AEM releases and delivery dates here :
Adobe Experience Manager Help | AEM maintenance releases roadmap
As far as I understand, there isn't a pre-release notes until the SP is released. If you are looking for anything specific that you are expecting as part of the SP, you could check by creating a ticket in daycare.
I think you have to keep an eye on Adobe Experience Manager Help | AEM releases and updates to see the updates when it is released. I am not so sure if they will pre-release the details about the updates. May be kautuksahni can help on that
This answers my question. I was asking for pre-release notes - what fixes/features are coming in the service pack (not the scheduled dates the service packs drop).