The "freely switch" here is referring to the W-chip multi-device support that will on the fly switch between any number of Apple devices based on what's actively being used at the time, without needing to do any manual connection stuff.
Other non-proprietary Bluetooth devices will generally do 2 devices at most, and getting that to work right with microphone input settings can be kind of a nightmare.
The "freely switch" here is referring to the W-chip multi-device support that will on the fly switch between any number of Apple devices based on what's actively being used at the time, without needing to do any manual connection stuff.
Other non-proprietary Bluetooth devices will generally do 2 devices at most, and getting that to work right with microphone input settings can be kind of a nightmare.