Historically, Detroit has been losing people (net migration) since the 1950s. I have not checked the data in the last 2-3 years. If there is a positive inward migration, check to see if the numbers really matter. There was such a surplus of housing, it would take a lot to soak up the inventory (or a lot of bulldozers). The peak in Detroit was over 2M. The last I looked the population was 600K to 630K. The actual city boundaries are very far apart. It is something like the 4 largest city in the USA by area. Lots of infrastructure to pay for.
A lot young folks are moving in from the outer suburbs (where once their grandparents/parents lived) and buying houses to renovate and live in Detroit.
@john Corey those are some interesting points, the latest data I was able to find was the population hovering around 670k, and also that the bleeding has stopped in that those leaving are less than 1%, I think it was .06%.