Don’t even need a snippet for that
Create your second content area as a textarea TV. Let’s call it ’contentB’.
Create a radio button type ’content selector’ tv called ’contentSelect’.
In input option values:
Content A==[[*content]]||Content B==[[*contentB]]
Default it to:
And in your template, replace [[*content]] with the [[*contentSelect]] tv.
Then the user can switch between content using the radio button. Easy
If you wanted to incorporate the ’auto publish’ date, it would be fairly easy to write a snippet that checks the current date against the ’auto-publish’ date then switches the content if conditions are met.