Ok, I might've been wrong.
Just found this:
Hawk-Eye to debut at Memphis tourney
Tournament director Peter Lebedevs said the Hawk-Eye instant-replay system, prevalent at Grand Slam tournaments and upper-level events on the ATP World Tour, will be used at this month's RMKC for the first time.
Lebedevs said the tournament found a local partner, the West Clinic, to help with the cost. Lebedevs wouldn't disclose the cost, but two years ago tournament advisor Bill Rapp estimated the expense to be at least $75,000.
Lebedevs said the fan experience will be enhanced by the addition, which will require 14 cameras placed around the club's Stadium Court. With the system, the players are able to challenge a limited number of lines calls during a match.
"It's a commitment to continue to improve the tournament, and the players wanted it," Lebedevs said. "This takes us to the level all the (ATP World Tour level) 500 events have. It's a great thing for the tournament."
I guess we'll see once live streams start.
yep it's there. Stakhovsky just went through all his challenges in set 1 vs Milos (got them all wrong)