I'm not sure of the practical implications for someone looking to use it in a design project. Who would have standing to sue for infringement, and in what situations?
If true, the practical implication is that A) Public Sans is in the public domain within the USA, which means people there have freedoms in using it that they wouldn't otherwise have; and B) their current license is incoherently obscuring these freedoms.
The GSA can't license something that is in the public domain. Should they recognize this fact, it will make clear what people can and can't do with the font.