Except according to this, it wasn't. Ever. Which means that 100% of those "confirmed sources" were guesses and hearsay.
http://www.polygon.com/2014/6/5/5782...lin-kaepernick
And there you have it. Why do people just believe stuff without legitimate evidence? On this particular topic, the "evidence" consisted of various video game reporters and news organizations not understanding why tattoos were done away with, and making an educated guess, and then quoting each other. (*you'll note that tattoos were still in PS2's version of Madden after the exclusive license...)
EA was never forced by the NFL to not do tattoos, at least according to the above link. They state here that the reason is fear of lawsuits by tattoo artists. The problem is that they had generic tattoos at the time, which makes it less believable. My guess is that at the time it was really a combination of both an unwillingness to deal with tattoo artists and and unwillingness to allocate resources to tattoos, particularly if they were going to be fake anyway. Why? Generic tattoos look fine on PS2, when the resolution is much lower and the graphics are far less realistic. But on 360 and PS3, generic fake tattoos would look pretty crappy. And real ones would require taking the effort to track down tattoo artists to gain their consent.
The funny thing with this topic is that so many people say things like "confirmed by multiple sources," but no one could ever actually produce one that has any evidence of the claim when pressed. They just at best would post a source that made the same claim, without the original primary source as evidence. Bottom line is it just "made sense" as an explanation, and everyone just assumed that the person they heard it from got it from somewhere that got it from somewhere that was legitimate.
No, what it puts to rest is the PURELY UNSUBSTANTIATED SPECULATION that the NFL ever even had a stance. See above.
The explanation was made up out of thin air, and then repeated until it caught on and became "truth" in the minds of most of the collective Madden consciousness.
And here's why it caught on so well: