Keep in mind, whenever you use the "and" to differentiate between two commands, you must make sure each command you speak is complete.
The announcement about the update was done by the Made by Google Twitter page.
Google Assistant's biggest selling point is just how smart it is, and on smart speakers that especially shows its value. Rather, users needed to say something like "turn off living room and turn off bedroom" to accomplish that task. However, the tweet has been deleted, possibly indicating the feature is not quite ready and may take some time before the official re-announcement. It doesn't mean much in the way of saving time-you'll save a few seconds, at best. Unfortunately for Google's global customer base, multiple queries is only available in the English language for the time being, in the U.S., U.K., Canada and Australia. Each command must also be the sort of thing Google Assistant can respond to on its own without further input or clarification.
Right now the feature works in English-speaking countries like the US, UK, Australia and Canada.
With little fanfare, Google has bumped the number of simultaneous queries and actions its Home smart speakers can handle at once. For example, instead of saying "OK Google, what's the time in Shanghai and what's the time in London", you can simply ask, "what's the time in Shanghai and London" and get two separate answers based on your question.