They discussed the trademark issue a bit in their filing-
https://creativecommons.org/wp-content/uploads/2016/10/CC-Un...
The CC logo and icons as a matter of trademark law are governed by CC’s trademark policy, which specifies conditions of their use “in a manner reasonable to the medium and context.”
According to Unicode criteria for encoding symbols, a trademark weakens, but does not disqualify, the case for encoding. As such, we would like to address this point directly, in addition to emphasizing the criteria that strengthens the case for encoding. So as to be sure there exists no misunderstanding, CC is seeking inclusion of the CC logo and icons in the Unicode standard notwithstanding that CC asserts trademark rights in its logo and icons.
The aims of Unicode and the CC trademark policy are not antagonistic to one another.
It is perfectly consonant with the purposes for Unicode to allow trademarked logos and icons into its standard without jeopardizing trademark rights of the requesting organization. Especially where, as here, there is a clear and public trademark policy by the submitting organization in place that clarifies when and how the logo and icons may be used, and such marks are ubiquitous.
Though the CC logo and icons are trademarked, they are a widely-used functional marking tool that indicates permissive use as an alternative to the well-known © symbol, followed by the icons that represent those terms.
As such, they were accepted and celebrated by MoMA into its permanent collection,6 alongside universal icons such as the @ symbol and the International Symbol for Recycling—both of which are encoded in the Unicode standard. Encoding the CC logo and icons in UCS would more easily enable creators to mark their works as consistent with CC’s trademark reasonable to the medium and context, in this case within text-based editors.