User blog comment:Cristina7/Introducing Discussions, a New Platform For Engaging Your Community/@comment-25648422-20160909022021/@comment-26402117-20160909174232

To go deeper, there were blocking technical issues with the creation of a portable version of the Forum feature, which operates on MediaWiki. The Ember framework is what staff used to depart from MediaWiki, which you'll recognise from the Mercury skin. However, that means they would need to rebuild a number of features the current Forums have to work on the Discussions framework - and also code MediaWiki formatting back into the Discussions to give us the wikitext we want.

I relayed quite a few issues to staff, like a missing global header and wiki navigation, niggling issues I found with the mod tools and more.