No, it will not create a Microsoft teams team automatically.

When you create a SharePoint online team site it will show you option to create a Microsoft teams and connect the SharePoint site to it like:

Team sites that are not already connected to a group will first need to connect to a Microsoft 365 group before they can be added to Microsoft Teams.

Reference: Create a Microsoft Team from SharePoint

No, it will not create a Microsoft teams team automatically.

When you create a SharePoint online team site it will show you option to create a Microsoft teams and connect the SharePoint site to it in the lower left corner of the home page of your team site:

Or you can find the Add real-time chat entry point in the “Next Steps” panel which is accessible from the top right section of your team site.

Team sites that are connected to a Microsoft 365 group in SharePoint can easily add Microsoft Teams. Team sites that are not already connected to a group will first need to connect to a Microsoft 365 group before they can be added to Microsoft Teams.

Reference: Create a Microsoft Team from SharePoint