Yesterday, for a couple of hours, the DnD Beyond main menus were given a new look and reorganized. Great. Then they disappeared... I guess it was a test? I hope they implement that change soon.

It was the intended new look but it had some bugs that affected some users, so they rolled it back. It will return. 

Quote from Azran_Anke >>

Quote from Eldamel >>

Yesterday, for a couple of hours, the DnD Beyond main menus were given a new look and reorganized. Great. Then they disappeared... I guess it was a test? I hope they implement that change soon.

 What the hell are you on ?? It was atrocious, ugly, aseptic and corporate as heck. It just made more place for ads, the agencement was stupid, the cool illustrations serving as visual cues were erased for some unpalatable bland-ass column and all that without even being actually more practical, just lazier. The worst being the change from simple overflow seamlessly opening the tabs to a -click and animation-.
How old are you ? 60 ? That type of UI design felt like a 10 years drawback so much it looked outdated. That was NOT an improvement.

 You are free to think whatever you want. Me too and I loved it!. I found it simpler, easier, more logical, and more modern.

It worked really well for me. I know some people were having some issues, so it makes sense that they rolled it back for the moment. However, my experience on the desktop and mobile were both improved somewhat. I think it benefit my mobile experience slightly better though. Looking forward to it returning, hopefully after the upcoming maintenance.