Apparently the idea to open the season against the Rangers came from Ticket Sales.
George Postolos, noting that Sales had concerns about moving to the Americal League:
“One of our ticket sales people raised his hand and had an idea that we would start off the season by playing the Rangers at home and that that would be a good way to celebrate the move to the American League West and them becoming an intrastate and intradivision rival.”
So there you have it.