In response to strong feedback about certain features and functionality missing in new Google Sites, classic Sites creation has been re-enabled in U‑M Google. This decision was made to minimize impact to fall term coursework requiring those features. Classic Sites creation will be available until closer feature parity exists between classic Sites and new Sites. The main impact you will notice is that sites.google.com now delivers you to the classic Sites page rather than new Sites.
We emphasize the importance of using new Sites whenever possible. This will reduce potential impacts when Google retires classic Sites, including a required effort to self-migrate your classic Sites. You can find the new Sites page by clicking New Google Sites in the left panel of sites.google.com or in Google Drive by clicking New > More > Google Sites. We will closely monitor as Google continues to improve new Sites with features and functionality currently available in classic Sites.
To reiterate, this is temporary. We strongly encourage the use of new Sites, as Google will eventually retire classic Sites.