Is it actually available for Cam v3? I know Cam Pan v3 has had it for a couple of years, and I’ve been using it on that and Cam OG. I don’t have any (non-Pan) Cam v3s to test, though. I know a couple of years ago they said it would be extended to Cam v3 “soon”, but then they changed messaging about that. 
I haven’t seen anything from Wyze recently about any changes or updates to this feature, but I see user requests and suggestions about being able to use additional cameras as chimes (especially for Cam v4) from time to time. My personal bias would be for them to change the name of the feature and enable it for as many cameras as possible, including other doorbells, floodlights, and other outdoor cameras. In addition to that Wishlist link, you might want to check this one:
As with any Wishlist topic, you can visit that one to click or tap the Vote button above the initial post and share your ideas and use cases in the comments to show your support for the product and feature request/suggestions that are important to you.