Zigbee Alliance renamed themselves to the CSA. Can companies still keep making Zigbee devices after Matter? Sure, it's not impossible, but it's not really going to happen much more than somebody producing anything else obsolete.

The fact of the matter is that Zigbee isn't competing with Matter, it's being replaced with Matter. Rebranding may not be the best choice of words, but I think you're missing the point.

If it was MS, it would start as ZigbeeSpecial 1, followed by ZigBee 5 and be incompatible with ZigBee 3.0

edit: Just in case anyone is not following C# developments

Old: .NET 1.0 … -> .NET 4.7 -> .NET 4.8

New and not compatible: dotnetcore 1 … -> dotnetcore 3 -> .NET 5

And of course, there is their ORM which did not drop the "core" part, so for .NET 4.8 there is Entity Framework 6, the version for .NET 5 is called Entity Framework Core and reached 6 as well last year. For ASP.NET (that is, on .NET 4.8) MVC 5 is the current MVC solution, I think for ASP.NET Core (.NET 5) MVC 6 might be, but despite actually working with those technologies, I’m not sure.

ZigBii