From Seeking Michigan website which has Michigan death certificates:
On September 1, 2019 digital collections currently available on SeekingMichigan.org will move to Michiganology.org.
Further down in the message the following information:
Q: What about all of the URLs of death certificates that I put on Find a Grave?!
A: We tried very hard to make something work for this problem. But in the end, there is no way we can redirect the URLs to Michiganology.org. We are working with Find a Grave, Ancestry.com, and FamilySearch.org to include a message on items that would have links back to SeekingMichigan.org. While we cannot redirect these URLs, we can communicate that the items can be found on Michiganology.org. We caution you to not use URLs in this way. Rather, download the image and upload it to other websites (with citations of course).
It doesn't mention Wikitree, but obviously those links aren't going to work either.
Another reason to have complete citations other than URL's!