Hi @tonyhxh,
The blog states:
"
Customers with active users of these features will get an automatic extension until January 31, 2020 or the expiration of their existing Office 365 subscription term (whichever is longer).
"
From my understanding, the HTTP action should be still available to use, but if those HTTP actions has not been used with the source outside of SharePoint and OneDrive before, then it should be not available to use it with that purpose.
The restriction here should be mostly focused on the data and the corresponding API access.
I think there should be blogs announced on this soon at the Microsoft Flow official site.
Regards,
Michael
