User blog comment:MisterWoodhouse/The first migrations to the Unified Community Platform/@comment-45511117-20200603234658

"Special:Forum is a feature used regularly by fewer than 100 out of over 350,000 wikis, and the code for it is quite old, making it a nonviable feature for porting to the new platform. With continued enhancements to Community Feeds/Discussions and the availability of wiki-style forums through the DPL extension, we have decided to retire Forums in the lead up to the UCP release. At the latest, we will have Forums retired by mid-January."

The code doesn't look old, and the way it's formatted is part of what makes FANDOM FANDOM. I seriously don't want want Forums gone.