Heads up, you PNG'ers out there...

The beta version of Photoshop now has a Remove Background feature that blows away all other automatic background remove tools. It's not perfect, but it may...just MAY...be good enough to pass the moderation process. Or will when the non-beta version is rolled out in Photoshop proper.

I don't submit transparent PNG's myself, so I'm only somewhat aware of the tolerance levels imposed by the moderators. In any event, give it a try. And note that you do need to have the removal process work on the server size (the Cloud), not locally, to get the best results.

I've posted two examples below. I removed the background (it's available in the floating contextual menu bar), then placed them against colored backgrounds. The process did NOT work as well as it did in PIXimperfect's YouTube video, but I was working with low-res examples, one of which in particular lacked sharpness.