The advice against pressure washing generally stems from days of yore when "sealed" really meant a dust shield in close proximity to prevent general particulate intrusion. The term "sealed" was meant to distinguish from "unsealed" where the bearing balls were plainly visible to both the unaided eye and whatever sand happened to be nearby. Think of the difference between an American Ashtabula bottom bracket versus the tin cover pressed onto the cone of a wheel bearing. These bearing were intended for regular disassembly & servicing owing to their exposed nature and chemistry of the available lubrications of the time.
Modern rubber sealed bearings are unlikely to get water infiltration owing to improved design. The pressure of a jet of water on the rubber seal can actually possibly make it seal harder depending on design. Though bicycle bearings are friction sensitive to the end user and such design is rarely employed outside of some cartridge-style square taper bottom brackets.
Generally the seals in a cartridge style bearing are inserted into the cartridge and the assembly is behind a shield/flange/baffle of some sort. Observe the flanges on an axle endcap. Or the dust shields of a quality headset... The purpose is to take away any direct path and deflect the energy of any incoming jet stream before the rubber seal so that the rubber seal can do it's one job, keeping dust out & keeping lube in.
Your bike is designed to operate in the rain. I think general advice ought to be updated to: "Pressure wash bearing areas no harder than would be experienced by rainfall." But, that may be too much nuance for many people, especially people who have no idea what kinds of bearings they have. Thus the general: "Thou shalt not!!!" still persists.
Last edited by base2; 09-03-23 at 07:11 AM.