It could be, but a DD215 was initiated to correct his DD214 in the 90's so it's more likely that DOD has simply modernized it's equipment since the original.
Among the fields in proportional font are the following:
Much of the information in the proportional font is stuff that one might use a lot, and which--if one was a poor typist--one might want to rubber-stamp. I wouln't think rubber stamps would work well with the ubiquitous carbons, though, and find myself a bit impressed with the size and detail of some stamps like the "remarks" column (the zero and the "NONE" indications would appear to be part of the stamp, if it was one). It would also seen odd that "SINGLE" (under marital status) wouldn't merit a stamp.
I don't know if the use of proportional fonts for the common text indicates anything, but it does seem a little odd. Of course, it's possible that's because I'm a good enough typist that it would be easier to type some of those things than use a stamp; that might not have been true for everyone.