The article -- really a synopsis by the author of his book -- isn't silly in the least.
The era of easy annexation is, for the most part, over. Though laws vary by state, it is generally impossible for a city to involuntarily annex another incorporated community. Suburbanites have lately been wise enough to read the handwriting on the walls, and have incorporated areas which would have been in the path of annexation a few decades ago. Many cities are now "landlocked," with no way to expand their borders. As the whole metro area grows, more and more of the high income areas, in addition to retail malls and office parks -- all high tax revenue sources -- are being built outside the city limits. And the city gets poorer, and tax revenues decline, as the middle and upper classes flee to the suburbs.
A primary thesis of Kurtz's book is that the Obama Administration will seek to destroy the "protection" provided by the incorporation of suburban towns. They may, for instance, seek to permit or encourage "tax overlay" districts, based on a referendum of the entire metro area. So, if such a tax referendum passed by a large enough margin in the center city to offset its defeat in the suburbs (a likely outcome, as it would amount to a wealth transfer from the burbs to the city), the tax, and whatever urban-oriented projects it funded (streetcars, for example) would be implemented. Similarly, the Administration may seek to combine urban and suburban school districts, by bringing legal action (hello, Holder) to make a metro-wide vote on the question binding. Again, a likely outcome: the combined system would get overwhelming support within the center city (why wouldn't it?), likely enough to overwhelm the "no" vote of the suburbs.
Local government sovereignty is very much in danger. Anyone who can't see that is being, well, silly.
Here is a review of the book, Spreading the Wealth: How Obama is Robbing the Suburbs to Pay for the Cities, by Ron Radosh of PJMedia.
What has gone of for over 40 years is cities expanding by incorporating unincoroporated areas. They did this to increase their tax base.
Existing city residents paid for the exapnsion infrastructure (and often enticement so developers) for these new areas. Once people moved into the new areas, these new taxpayers were tapped to pay for the next new expansion and its infrastructure costs ... and so on and so on.
This is how suburbs were created and why we have multiple rings of suburbs around central cities.