Do pros ride with 1X configuration on some courses?
Yes, they sometimes do (or at least announce/intend to), here are two examples:


  This is the 3T Strada that Aqua Blue Sport will ride in 2018, making
  the Irish-based squad the first pro cycling team to use a
  single-chainring drivetrain.


Source


  One ring to rule them all: Tony Martin's Canyon Speedmax 58x11-32 on
  the world champ's time trial rig


Source