Why has this only been deployed today, just as the black box possibly starts to run out of charge?
Since Tireless was reported to have arrived in the general area on Monday 31st, that press release would seem to have been substantially overtaken by events.
Dangling a single microphone on a rope would seem to be less effective way to hear high-frequency pings than having seasoned and skilled ears using a big computer and a phased array of at least hundreds of them located beneath the thermocline. If I wanted to bet on the most likely to be successful, I'd put my money on the submarine.