In the end, what it all boils down to is... Do you count "gameplay releases," "marketed publisher releases," or some other measure?
Pac-Man plays identically, and the on-cart code is essentially *identical* other than the documented "cover up" of the Atari logo. So it wouldn't count as a separate release from the "gameplay releases" perspective. But would Auto Racing count as two then? Since it had two distinct game play modes? (Although the counter there is it wasn't marketed as a different version, and the alternate play version was accessible with a keypad combination. If the original Mattel Electronics Auto Racing only had the one gameplay method, and INTV had released an otherwise-identical version, but with "Super Pro" branding and the turn gameplay change being the only gameplay change, would *THAT* count as separate?)
If you count "marketed publisher releases", then the two versions of Pac-Man would be separate. Noticeably separate boxes (not just removing some branding like NFL Football to Football,) different cartridge styles, etc. But then, why wouldn't the Intellivision Inc de-branded sports titles be separate?
I think 125 is a good "base number" to go with. It is a number that includes each separate *game*. Many people here *DO* get in to collecting packaging variations (Intellivision Inc releases vs. Mattel Electronics releases vs. Sears Super Video Arcade releases vs. international releases, etc, etc, etc...) But that's a much, MUCH larger can of worms to open.