With the recent updates in marketing, I have seen in multiple environments from my clients that the personalization bottom for emails is deactivated when the client copy and paste an html when creating an email. My clients have marketing designing teams and they design the emails in their software to meet their privacy and accessibility standards. When copying this code into the email creator in marketing, the personalization bottom dissapears or is grayout. In an article published on 5/5/2022(Use custom attributes to enable designer features in templates (Dynamics 365 Marketing) | Microsoft Docs) comes up that the solution is using meta tags. This is new and it should not be required. It would be great to have an standard email editor that allows you copy and paste html without having to add any extra coding or perform more edits after being copied.