A beacon that is "hot" is one where satellites are continually being acquired.
Not sure where are you coming from. The only reason to "acquire" anything is for a GPS to calculate its position. Few airplanes (at least in the GA world) are equipped with the latest GPIRB beacons that contain their own GPS unit. Normal ELT beacons were never designed to "acquire" anything. They only transmit, don't receive anything. They are supposed to be totally dormant (saving battery charge) until triggered by a crash or manually turned on by somebody on the aircraft. You buy today a brand new $800 K Cirrus aircraft and it comes with a modern ELT beacon (121.5/406 Mhz) but has no GPS.