A family of Microsoft word processing software products for creating web, email, and print documents.
Hello Jackson,
Thank you for posting your query in Microsoft Office Community.
This is behavior which you've specified is by-design.
When you split a document, the sub documents will use a different template. But when you view them from the master document, the sub document will take the template used by the master document.
If you think the carry over feature of style is important and want Microsoft to include it, provide your feedback through the following link.
http://office.microsoft.com/en-US/suggestions.aspx?origin=FX101741961&CTT=114
If you have any other questions related to Office products, reply and I’ll be glad to assist you.
Thank you.