To me it implies it's from the boneless part of the chicken, not that it's deboned dark meat which is different and fair to expect a bone in since deboning is difficult to do perfectly en masse.
This is using the logic around fish, where they take out the majority of bones but you can always still expect a small bone. But that doesn't make sense for white meat in chicken.
"Boneless" even as a style of preparation strongly suggest, well, removing bones.
To me it implies it's from the boneless part of the chicken, not that it's deboned dark meat which is different and fair to expect a bone in since deboning is difficult to do perfectly en masse.
This is using the logic around fish, where they take out the majority of bones but you can always still expect a small bone. But that doesn't make sense for white meat in chicken.