Document modes deprecation

Hello,

I am trying to understand the full extent of the impact of the deprecation of Document modes based on this post.

http://msdn.microsoft.com/en-us/library/ie/dn384051%28v=vs.85%29.aspx

Our product leverages quirks mode in certain areas. With these deprecations does that mean that with IE12 those components that remain in Quirks Mode will simply not work, or they will be rendered in correctly?

I am trying to get an understanding of the potential scope of the issue in order to allow time to resolve the issue before the issue is forced.

Thank you