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I'm glad to have you here. I'm sorry I reverted your first edit. My opinion (though I could be wrong) is that Previous Destinations of the month is really an archive page, and that the photos in it shouldn't be substituted unless they no longer exist and turn into red links. If you would like to argue the point, you are welcome to start a new thread at Wikivoyage talk:Previous Destinations of the month. But there are ample active pages where new photos could be a great help. And I liked that photo of Cape Town's City Hall, too!
All the best,