Here are some bounds and data points.
The Dartmouth BASIC specification does not have ? as an abbrevation (circa 1964).
I think all versions of Microsoft BASIC have this shortcut (circa 1975).
Palo Alto Tiny BASIC (li chen wang) didn't use this convention -- instead it
used "P.".
Wang BASIC (circa 1972) didn't use this convention.
From what I can tell, DEC BASIC didn't use this abbreviation.
HP BASIC (at least the version on the 9830) doesn't either. Of course HP
BASIC was odd anyway, in that PRINT was what other BASICs called LPRINT
(it sent stuff to the printer), while DISP was what everone else called
PRINT (to send stuff to the display).
-tony