TL;DR:

From today the license applied to the project will be the Apache 2.0 license with an extra line forbidding usage of the codebase as an integration or app to Atlassian's Confluence or Jira products.

While it's disappointing to see the additional restriction, it's better to have a project the devs find sustainable than to have nothing at all. It seems like the goal of this change is to protect their main source of funding.

Worst case, people can fork the code before the change.