Thanks for writing. Did your plum produce many flowers? If not, then it may have been overpruned. If it did flower well, then there may be another issue such as no pollinators. Most plums bear best when there's another variety nearby to pollinate it. If one of your neighbors, for example, had a plum and cut it down, you may have lost the pollinator.
I'd wait and see what happens next year --- if pruning was the issue, then it should flower and fruit well.
---Justin, Senior Garden Editor, BHG.com