wheel bearing re-grease?

I've ordered two rear wheel bearing from 1stSubaruParts.com The fellow there says my mechanic does NOT need to use different grease than they come packed with! Has something changed? I thought the bearings HAD to be re-greased and that this was a primary reason so many failed. What's the real story?

Also, does my mechanic need any special tools he might not normally have to do the bearing job?