The StackExchange drop down menu from the main or meta pages of a site contains a link to chat in the Current Community section. Instead of linking to the list of site rooms, this links to all rooms.
I believe this had previously linked to just site rooms, which the link shown below seems to confirm. I expect this would be much easier for relatively new users wanting to chat about the specific community they are reaching chat from.
Is this affecting all communities? I have confirmed that both Computer Graphics and Programming Puzzles & Code Golf have chat links to all rooms instead of site rooms.
From Computer Graphics, the chat link is this:
This certainly looks like it is intended to show site rooms, but the page that is displayed lists rooms from many sites, and says "a list of all rooms" at the top, with the tab title being "all rooms | chat.stackexchange.com"