Can someone please explain how this image falls under Intellectual Property refusal? Similar images were accepted before, but today it was rejected due to intellectual property.

“The 11-point maple leaf and the Canadian National Flag are protected against unauthorized use for commercial purposes under paragraphs 9(1)(i) and 9(1)(e) of the Trademarks Act.”

As for your other question, yes and no. An occasional IP submission with an IP issue would unlikely be cause for an account ban, but out and out stealing of another person’s copyrighted material would be just cause. I also imagine that some moderators sometimes miss an IP issue, accept the asset, the the owner of the copyright issues a complaint. That could cause a ban, at least a temporary one, while Adobe investigates the issue.