I completely understand the license change. I mainly hope that interoperability will be kept intact by any proprietary implementation, but I would expect that to be trivial in practice.
The controversy bit is more about the statement that this brings more freedom than about the license change itself. That the license change can have very positive consequences for free software users is obvious. It is arguable whether it brings more freedom by itself however.
It would be interesting to read a bit more about what kind of adoption and what kind of benefits for Jitsi are expected with this change. I think Jitsi's strong interoperability can really make it shine.