This is not so much a bug report as a suggestion for improved documentation. A colleague and I were working on some plots and stumbled across the initially confusing behaviour that ax.get_xticklabels contains a list of ticks without any text yet, and that a call to plt.draw() is required before the tick list is populated and can then be modified. This problem has apparently also confused some other people: https://stackoverflow.com/questions/32700935/get-xticklabels-contains-empty-text-instances

I've sent a pull request with additional explanation in the documentation.