The BC Links have been used all season with a variety of beacons, with no interference being reported. It's possible what you were hearing about is the magnets in the mics that patrollers use with their VHF radios. There was concern, quite a few years ago, with certain models of Pieps beacons and the radios used by patrollers. When those were put too close together it was possible for the Pieps beacon to turn itself off. However, that was due to that particular model of beacon using a magnetic on/off switch. Fortunately, the Tracker, as well as many other beacons, uses a mechanical switch which won't be affected at all.
If you put the beacon extremely close to the BC link, it's possible that you would experience a very slight decrease in range, much the same way you can if you keep it very close to a cell phone. (also not really recommended)
Anyway, hope this helps clear things up!