Nope, the data is defintley in there, thats why the sound roms for certain games contain both Japanese and English voices, also games like Scud Race, have the data for both Scud and Super GT title screens.

There are a few games that do require 4 new eproms for change, but these are the Australian versions only (and hence they have Australian version on the title screen, I've seen this for Virtua Fighter 3, Scud Race and Dirt Devils, but I am sure there are more).

It was the same for Model 2 also.