I'd also like to know more about this! I was going to sneak fonts from Adobe into my game but I think technically they're not allowed to be embedded in other programs according to Adobe's own terms and conditions? So even though they're free with Adobe, I don't know if they're okay seeing as it's not completely Open Source.
My next question would be about fonts that are free for Personal Use...I imagine they're fine? But I dunno, like you said, typefaces are a little tricky.