My guess is that Morganeers the world over may be somewhat sensitive to greasing, more so if they have spent time on any of the many forums or talking to other Morgan owners..? Also those of us more mature types who have a history of messing about in and under vehicles, some of which may have been older than us, will remember a time when even door hinges might have had grease nipples, let alone steering, suspension and drive line components..?
I well remember when Datsun first introduced their cars to my part of the world, their track rod ends had little screw in plugs that when removed a grease nipple could be screwed in, to keep those of us us who were keen on greasing every nipple, happy... I had involvement with a few Datsun`s belonging to family and friends and as best I can remember I never replaced a steering or suspension component on any of them over the years. All of which was a world away from the usual Ford, BMC and other manufacturers, where for each and every MOT there would be the usual replacements required if not annually then semi regularly at the least... I guess it kept small garages busy and the parts manufacturers and suppliers happy..? I suspect Datsun and others altered our expectations in time...All just part of the evolutionary processes...whether good or bad, I leave it to you to judge..
As for the UJ...I guess if there might be no sign of it having leaked it`s initial lube at the time of manufacture, then I guess it might still be in there, and if there is no play and it has covered a few miles of enthusiastic driving in your ownership, then it just might be fine to leave it be....? But then IF there is a grease nipple...????