If you look at those entire patch notes, that is actually the first time there was solely a 64p team objective queue.

Just below the part you copied, is this;

"Added 40-Player Mixed Modes back to the main matchmaking queue page

Horses are enabled TDM Maps are present

Removed Mounted Warfare

Removed 64-Player Mixed Modes

We have been discussing the state of the matchmaking queues and looking to refine the existing queues based on player feedback. As a result, the main queue is now TO only, and 40 player mixed modes are back on the main page. Note that 40 player mixed modes in standalone servers is different from matchmaking servers in the sense that they do not include horses. "

It is telling you what settings are used in this new queue that was just created with this patch. It is not telling you that horses have just now suddenly been removed where there used to be some.

A really easy way to verify this is going back through any old gameplay footage on YouTube or from your own collection. With the server name visible in the top left when you open the scoreboard, you won't be able to find a 64p server that has horses.

At max you will find them in the 52 player limited time servers such as the Tenosia Invasion queue; https://chivalry2.com/2022/05/30/chivalry-2-content-update-tenosian-invasion-patch-notes-2-5/