It really doesn't seem like a material change to me. Again, IANAL, so if there is some reason to believe these things would be disallowed under the old TOS, I'd like to know, but it sounds fairly straightforward. While Instagram may have had a more difficult case under the old TOS, and may have had to be more careful about the dispensation rather than just doing a blatant "stock photo"-type interface, I could definitely see an attempt at the argument that representation in "any media formats through any media channels" covers Instagram in most cases of what would be considered "transferred sub-licensing".
The clarifications, of course, are intended to clarify the consent they're taking. I'd be interested to know their motives for this; as I speculated in the parent, does a new law take effect in an important market with regard to advertising? Are they just trying to play it safe? Are they going to make aggressive moves into this kind of space (reselling user photos, using users' profiles without consent in advertisements) and wanted to ensure that they didn't have to deal with any lawsuits upon launch?
I will agree that the new TOS allows them to use your profile and likeness as they see fit, which based on my simple layman's reading, isn't included in the old TOS.
Just thinking out loud here, move along.