Every Brother and Sister should have on them at all times a copy of the Master Agreement. I'm appalled, but not surprised to hear a question like this. It's quite disappointing.
Our local prints it as an easy to carry handbook, the size of a cell phone. It has come in handy on many occasions. Several pages in mine are ear-marked because of the frequent turnover of part time management. We even go so far as to have a couple dedicated copies in the office for management to review an any time. Has saved us many a grievances.
ARTICLE 40 - Change of Operations...
The parties agree that there must be a procedure to permit timely
and efficient Change of Operations in order to meet marketplace
demands and changing customer needs. The Employer agrees that
service centers and facilities covered by this Agreement shall not be
transferred, changed or modified without notification of and discussion
with the Local Union in accordance with this Article.
You can read the rest of it in the 2018-2023 Freight Master Agreement.
Here's a link to one. >>>
UPS FREIGHT 2018-2023 NATIONAL MASTER AGREEMENT
Again, EVERY Union Brother and Sister should have a copy of this, know where to find a copy and to have read it front to back.