Too early to tell - usually they'll settle on something with a balance of those main values. If matrix is truly the new IRC then perhaps that, though it doesn't seem mature enough yet and it seems like it might be costly if one needs to host non-text content. Furries contain both highly technical people and also very low-tech artists so any platform that requires a lot of maintenance can be a non-starter. Signal seems like privacy over expression. Maybe this is the time that they'll make their own.
Most of that crowd that I interact with was already off Telegram to begin with, and (in some cases, begrudgingly) run their own Matrix instances.
I think if you interact with non-tech-users, Signal is the go-to; Matrix has way too many thorns for normal users to put up with in comparison to the alternatives.
As a furry: lmao no Matrix. Matrix does not get the job done at all. Profiles stored on the server you decided to join? Lots of silly design decisions.
Also the whole "furries make the internets go" is not really that true. There are certainly many of us in tech fields but going to meets/cons the average furry is not working in technology. The whole "suspiciously wealthy furry" thing just arose from the divide between tech worker and retail worker within the community. Gotta remember that most furries are like 16-25. Many tend to drop out or leave the community over 30-40 or so.