These are sealed [not shielded as stated] only using lip seals, so should work fine BUT the original fill grease would/should be lifetime & better quality grease one would think.
FOR STARTERS, note that most sealed bearings come pre-greased from the factory with a 25%-35% grease fill. This is all the grease the bearings will ever need, because the relubrication interval (explained below) is longer than the expected life of the bearing. DON’T JUST GUESS. It can be...
i have pulled the seals on new bearings to find a dab of what apears like vasaline ,in a new bearing ,i cant recal what they were for , thinking ,on the deck of my ride on mower .i packed them with wheel bearing grease before installing them