Enabling the Communication Site Experience on a Classic Team Site
A classic site can be a big eye sore in your intranet. You might've tried creating a modern site page on your site but still aren't satisfied because of that pesky left navigation. With this new feature you can finally have the appealing look of a communication site applied to your classic sites. This feature will be rolled out to targeted release users by end of June 2020 and will roll out to everyone else the end of July 2020.
BEFORE YOU GET STARTED
This will only work on classic team site collections. This will not work on publishing sites, subsites, or any team site connected to a Microsoft 365 group.
When you make the change, the modern page will be automatically set as the home page of the site.
This will not change the site template. It will stay as a classic team site, your site will just have a modern communication page.
The SharePoint Server Publishing Infrastructure must be deactivated. If it was previously enabled you need to delete the Pages library (not the site pages library).
Site pages (modern pages) will be set as the default content type in your Site Pages library as well as minor versioning will be activated.
List and library experiences will not be changed.
You can use SharePoint Online Management Shell but I prefer to use PnP. As long as your site meets all the requirements you can swap out the <INSERT SITE URL> in the code below with your site's url and enable a new communication site home page.
Install-Module SharePointPnPPowerShellOnline Connect-PnPOnline –Url <INSERT SITE URL> –Credentials (Get-Credential) Enable-PnPCommSite