No, unfortunately when you copy and paste content into a template the formatting does not stay. Here's how to properly add content to a template via the source tab:
- Click the button that says Source
Copy all of the content there. Then create a new template, click the same button and paste that code into the Source code area and you won't run into the formatting issue.
- The other option, is to copy the text from the template, and then open a TextEdit file and paste it there. Then, re-select the text from the TextEdit page and paste it into a new template.
It may seem a bit tedious to takes these two steps, but this is actually standard behavior for most text editors to react this way to formatted text and these two options will either carry the formatting, or strip the formatting depending on if you choose the first or second option.