Whether it matters depends very much on what sort of organization you are.
Discord is a multinational for-profit corporation planning an IPO. It takes payments from users in those countries, likely partners with companies in those countries, and likely wants to sell stock to investors in those countries. Every one of those countries has the ability to punish Discord if it does not obey their laws, even if it does not have a physical presence there.
The situation is likely quite different for most of the 23,306 Matrix servers that federate widely. The worst thing Australia, for example could do to one of their operators is make it legally hazardous for them to visit Australia.
It does not actually need to be configured in a federated state and frankly scales better when it's not. The login can be tied to anything or use it's own. From a modern SAML SSO to an old school forum.
You can run one for a few friends and it scales just as well as a private discord for a few friends. Just need persistent storage for media uploads if people are sharing video a lot.
We need more stuff hosted through obfuscated channels (Tor, I2C, etc) and more user friendly access to those networks.
This matrix discussion here is missing the point - many people don't want ubiquitous tracking of everything we do on the internet. You and matrix are seemingly not honestly addressing that point, because matrix doesn't seem different discord (in the requirements).
The difference with Discord is that Matrix is a protocol, not a service. It's made up of thousands of servers run by different people in different countries. Public instances may choose to verify users in affected countries to abide by the law; others may choose to run a private instance instead.
tldr, means for American firms to sue due to burdonsome regulations, also some contitution stuff.