One of the reasons Bristow winch gear down all started with the 139 when CHC took the CG contract in 2008. With the then 139, the aural alerts when coming into the hover with gear up for winching, were an annoyance and detracted from safety. Lowering the gear stopped this. Although with the advent of phase 6/7, these annoyance warning could be hushed but the precedent had been set and some people were not flexible enough to change.
That carried over to the new contract in 2015 operated once again by Bristow, with the intro of the 139 into Lydd and St. Athan.
It's not required to do it now as the warnings can be managed depending on your flight regime but try changing something in a big company!
What Bristow did on the 139 carried to the 189.