Option to Use Template Variables After Creating the Page

Problem Definition

When creating a page based on a template that have variables, we need to enter the values for those variables. However, once we are able to enter text in the body of the created page, it's not possible the use the variables any longer.

Case Scenario

1. Create a template with variables $manager and $dueDate.
2. Once I create a page based on this template, I enter "Eduardo Mallmann" for the $manager variable and "05-05-2016" for $dueDate.
3. Now that I'm writing the body content of this page, instead of entering the name of my manager and the due date manually, I should be able to use the variables $manager and $dueDate.

Example
Produce release notes $manager with the project due date $dueDate
This would generate the following text:
Produce release notes Eduardo Mallmann with the project due date 05-05-2016.