They couldn't do anything this late in the game if they wanted too, I worked for the USPS for two years, the bureaucracy is worse than even the DMV because everything also has to go through the union. Mail delivery schedules for the next couple weeks have already been made, they attempt to change them and call extra mail carriers in, they will have grievances flying left and right, either that or those called in will just take a sick day.
The USPS union has to be broken if you want real results.
I’ve been associated with a couple of USPS workers. They are very adamant: they don’t work for the USPS, they work for the union.