No. Once again, I will post Ancestry's Terms and Conditions: (emphasis added)
"Ancestry does not claim an exclusive right to images already in the public domain that it has converted into a digital format. However, the Websites contain images or documents that are protected by copyrights or that, even if in the public domain, are subject to restrictions on reuse. By agreeing to these Terms and Conditions, you agree to not reuse these images or documents except that you may reuse public domain images so long as you only use small portions of the images or documents for personal use. If you republish public domain images, you agree to credit the relevant Ancestry Website as the source of the digital image, unless additional specific restrictions apply. If you wish to republish more than a small portion of the images or documents from any of the Websites, you agree to obtain prior written permission from us."
Assuming these documents are in the public domain, there is no copyright violation and posting them to Wikitree doesn't violate Ancestry's terms as long as they are given credit for digitizing and making them available.
Part of the last sentence, "small portion of the images or documents", has frequently been misunderstood to mean only a portion of a page can be used. Their intellectual property claim is regarding the collection of documents they put together. They don't want users to republish documents in bulk without permission. "Small portion" applies to the collection, not part of a page.