Is it accurate to describe this as the public domain? I would expect that the bird logo still enjoys copyright protection, independent from its status as a trademark.

The final paragraph says this, among other things:

"The court ruled on a preliminary injunction request, so it’s not the final word on the merits. Still, it seems highly likely that the TWEET term and the bird logo have been freed from X’s trademark clutches. If so, it’s nice to get some cultural assets back into the public domain"

Seems kind of dubious to say the least.