pilot-Br. Caution not to mix things up !!
LHDs are monitored to verify the target level of safety of RVSM operations.This does not explain the problems Brazil ATS currently faces.
In your case the Legacy was flying exactly at the altitude it was set to fly : 37.000 ft, and so was the GOL 737 . Should one of them had an altitude deviation , not even a large one , as it is meant in this WP , they would have missed.
The Brazil collision has nothing to do with RVSM operations or LHDs.
The collision would have occurred the same below 290.