Microsoft has announced that Delve blogs will no longer be supported in 2020. The news is unsurprising because Delve blogs have not been actively developed for several years. Office 365 tenants with content in Delve blogs must figure out where to move the content to. It might be the case that you don’t need to do anything because the content isn’t needed. If you do need to keep it, you could move Delve blog posts to SharePoint news or similar repositories.