Many of the spring training gloves would be more along the lines of retail limited/special edition gloves, than a true PI ordered through the companies' pro dept.
The sheer number of gloves required to bring all of the new models down to spring training (not to mention gloves for minor leaguers, college players, and sample gloves to show to their better/bigger retailers), forces the companies to make fairly large batches of them instead of the way they would normally make a PI glove.
It's easy to see the difference between this PI Chris Young glove made for him...
and this duffle bag full of spring training gloves...