I work with a lot of large non profits handling their direct mail work.
While we do not interact with post office as much as we used to, it is very common for facilities to take sorting machines off line, move volume to different facilities, etc.. Nothing the post office does it done quickly, most things go through levels of review before moving ahead with decisions. As volume goes down, more and more of these changes are made.
Big mailers do more and more of the sorting/trucking themselves, similar to how Amazon does things with UPS, thus getting the best rates do to the fact the USPS touches the mail less and less through stream.
It is being politicized for several reasons:
Anti Trump
Postal unions don't want to lose jobs/hours
USPS - feel they are burdened with undo costs by government (mainly pre paid pension costs), so if Congress wants to allocate more money