Not at all.
That was from my Kubota tech (Dennis) at the dealership I deal with. Dennis told me the fluid level in the gearcase needs to be at the level of the rear PTO shaft seal but not above it, when the tractor is sitting and level in 2 planes because the seal isn't designed to seal a constant pressure from the fluid against it. Besides, the gearcase is lubricated by splash anyway.
Maybe yours is, yours is much newer than either of mine are. Mine are 2002 and 2004 M9's.
In my case, because I exchange pto shafts on my 2 speed (540 6 spline - 1000 21 spline), Having excess fluid in the gearcase only results in a mess when I exchange shafts anyway though I still back the tractor up on heavy duty ramps when I change them out.
No point in loosing expensive fluid on the ground, the fluid I use (Chevron All Weather THC Synthetic) is pretty expensive stuff. Last time I bought a drum, it was just over 100 bucks per 5 gallons and my units each take just shy of15 gallons on a changeout.
In reality I don't much care what you do. Just passing on my experience, nothing more.