XF 1.1 Outdated templates?

[Bubka3]

What type of task do I need to complete to fix this notice?

 

[Jake Bunce]

You need to revert those templates to apply new changes. But in doing so your customizations will be lost and will need to be reapplied.

Addressing outdated templates isn't strictly required. Though you may encounter minor style problems if you don't revert.