Quoted from LTG:
I suspect they don't have the rights to the Bally name.
Now on the SE and LE, since it's on the LCD, I suspect it's in the original software, and able to be used.
LTG : )
This is not really a complicated issue as reproducing a copyrighted logo by any means (including using it in an electronic form) without obtaining permission of the copyrights holder would violate US copyright law.
In the original MM, the Williams logo was clearly part of the attract mode game code that CGC has obtain rights to use; however, CGC expended resources to scrub this logo from the original code for use in MMr. By the explanation given here, CGC would have rights to leave this in the code, and it would have been easier and less costly to leave this code in place; however, this just isn't the case but is consistent with the explanation that Williams refused to allow the logo to be used.
The difference with ATMr is that the original Bally logo is being used, so it's being used either without permission (doubtful) or CGC has permission to use the logo and chose not to go through the added expense of printing it on the original speaker panel. Since the Bally logo is printed on the ATMr apron, I suspect the later is the case and has nothing to do with the software or trademark rights.
Sorry LTG, I have to disagree with you on this one, but for what it's worth I still think of you as one of the greatest supporters this hobby has.