The exchange protocol is like CORBA and the US tax system got together and had a baby. You’d also need an exchange server to test it with, and running an exchange server isn’t trivial.
The exchange support for Evolution never worked well for me. There was always something that didn't sync, didn't get detected, or wasn't supported.
I don't blame the devs, Exchange is a proprietary standard so you can't expect it to work well. It's like the reverse-engineered drivers for hardware the manufacturer doesn't bother to write Linux support or sufficient documentation for: it doesn't work great, but that's despite the devs' best effort, not because of it.
Matrix support is probably a ton easier.
Besides, matrix is designed to be implemented by multiple parties. Exchange isn’t. In fact, exchange is almost certainly the opposite.