For what it's worth, I have never changed wheel bearings on a bike purchased new. This includes up to 122,000 miles on a ST1100 ridden everywhere mostly 2 up. The other ST's (4) had around 75,000 miles.
Used bikes mostly required replacement.
When the bike is purchased new, remover the wheel, gently pry off the bearing seal. Wipe off the very small amount of grease and install a LOT of grease in the bearing.
Renew at about every 25,000 miles.
Bearings should be good for the life of the bike.