The only time I have come across this practice was at a certain FBO in the US, where it was SOP.
The reason was that if there was no pressure in the brakes, a longer runway could be chosen and a touchdown at the start would mitigate the risk of an expensive overrun.
The FBO owner told me that his insurance company had indicated that they would consider refusing payment if brake pressure was not checked in the air, on the basis that an overrun was an avoidable occurrence.
This was in the LA basin, where there was a choice of very long runways within a few minutes diversion from base.
I'm not commenting on whether I consider this good practice, just relating the facts.