No - Multiple Master Fonts can be used on any PostScript printer. Multiple Master Fonts need a new PostScript operator known as makeblendedfont. The current crop of Multiple Master Fonts supply an emulation of this operator so the printer doesn't need this operator.
A short tutorial on Multiple Master Fonts and makeblendedfont appears in PostScript by Example, by Henry McGilton and Mary Campione, published by Addison-Wesley.