And has Attanasio given any indication whatsoever that he will be putting the team up for sale? All signs have been that he intends to keep the team within the family for the foreseeable future. So, I don't quite understand where you are getting that from, and why you are treating it as a matter of fact.
Second, despite the constant relocation threats used in coaxing public financing for professional sports stadiums/arenas, they rarely actually end up coming to fruition. The A's and Ray's sagas have been going on for two decades now (virtually as long as Am Fam Field/Miller Park has been in existence), and yet both teams remain in their trash heap of stadiums (which AmFam field is currently not), with no resolution in immediate sight. The fact of the matter is that sports leagues such as MLB are loathe to relocate their teams, particularly where strong fan support for such team exists. That is clearly the case with the Brewers in Milwaukee.
Third, the Brewers are far more of an engrained institution in the city and the state than the Bucks were at the time they secured public funding for Fiserv Forum. Obviously, the Packers will always remain king, but the Brewers are right there after them. When the time arrives for these discussions, there will be strong headwinds in favor of getting a deal done.
If you ask me, while I appreciate the effort, this article is way too apocalyptic. The ballpark situation will sort itself out over time, and will almost certainly end with the Brewers staying put with either a renovated or brand new venue.