They did it.
From CBS Press Express:
March 10, 2015 – The CBS drama series CSI: CRIME SCENE INVESTIGATION has succeeded in shattering the Guinness World Records® Achievement for “Largest Ever TV Drama Simulcast” on March 4, 2015, “World CSI Day,” when 171 countries participated in a worldwide simulcast of an episode of CSI: CRIME SCENE INVESTIGATION. The episode that broke the world record was “Kitty” (OAD: 4/30/14), which aired as the planted spin-off for CSI: CYBER, the next generation and fourth series in the franchise.
The previous record for the largest TV drama simulcast was achieved by the special 50th anniversary episode of “Doctor Who,” in which 98 countries participated in November 2013.
The CSI episode aired in 171 countries at 7:00 PM, ET (12:00 GMT) and was streamed in the U.S. on CBS.com from 4:00 PM, PT to 12:00 AM, PT.
The global event celebrated 15 years of the CSI television franchise, one of the biggest and most successful series in the world, and the U.S. premiere of CSI: CYBER, starring Academy Award® winner Patricia Arquette.
The U.S. premiere of CSI: CYBER (10:00-11:00 PM, ET/PT) was first in its time period in viewers (10.46 million), adults 25-54 and adults 18-49. With live plus 3-day DVR playback, the premiere episode of CSI: CYBER added +3.38m viewers (13.84m from 10.46m), +1.1 rtg pts in adults 25-54 (3.8 from 2.7) and +0.8 in adults 18-49 (2.6 from 1.8) from its live plus same day averages.
And no, still no news on Season 16.