The first interpretation is the correct one:
One can use the ANT components (DLLs...) to communicate with ANT devices only. Communication with non-ANT devices must not use ANT DLLs.
This also means that implementations of the ANT+ Device Profiles, ANT-FS, etc. must not be used on wireless transports other than ANT.
Combo wireless devices that bridge between protocols or that offer multi-protocol support are part of the active ANT+ ecosystem today, and we expect that they will continue to add value and flexibility to products that connect into the ecosystem.