Hmm.. Maybe next year is an election year?!
When I was in graduate school, I took a course in Municipal Financial Planning taught by an adjunct, Mr. Lloyd Jones, who was then the budget director of Baltimore. He said, among many other things, : you, as a political official don't mess with the boys in blue, police and fire, or the teachers. Woe be unto the politician that does and wants to get elected.
Well, yes, but the rank and file think the our Mayor SRB has messed with them plenty (Buz doesn't totally agree, but gets the unions' point).
But perhaps she fully believes that the city will dramatically win the lawsuit the unions have lodged against the city because of the pension. Or, the announcement will simply keep the wolves from the door till after the election. Or the economy will suddenly get tremendously better. Who knows?