The Thread protocol is getting an update to version 1.3.0 to prepare the ground for the arrival of Matter, scheduled for the end of the year. So while Apple TV 4K, HomePod mini, Echo Gen4, Nest Hub/Hub Max, Nest Wi-Fi Mesh routers, eero Wi-Fi 6 routers and some Nanoleaf products can already act as a Thread access point , each creates its own Thread network on its own. Now (finally when Thread 1.3.0 has been deployed on each device, which depends on the manufacturer), these devices will be able to communicate with each other (but not necessarily interact), and will only create a single Thread network (which is the goal of the interoperability advocated by Matter).
As a reminder, the Thread low-power wireless protocol is part of the Project Connected Home over IP standard, or CHIP, now called Matter, developed by (among others) Apple, Amazon, Google and Zigbee Alliance. This protocol is supposed to allow each Thread-enabled device to assume the role of a repeater, which will have the consequence of being able to connect a device that is far from the bridge, but close enough to another Thread device. Matter was to be officially launched at the end of 2021, before being pushed back to fall 2022. Behind this delay, Tobin Richardson (CEO of the Connectivity Standards Alliance) highlights in particular the resurgence of the COVID-19 pandemic, the addition of many new companies (including Sonos very recently) and the challenge of providing development tools high quality software within the specification.