[jhgg]

For reference, this is the "contract" which TWiT are arguing. It's a reply from Ev, to an e-mail from Leo. The full contents are at the bottom of the filing[1].

>Just got your letter. Don't worry: We're not expanding to audio or video under the Twitter brand. That news story was the result of an over-zealous production company (and extremely sloppy reporting by AP). See our post: http://blog.twitter.com/2009/05/were-not-making-tv-show.html

There's a world of difference between "we are not" vs. "we will not". I am not eating a sandwich right now, but I will most definitely at some point in the future. One would have to be a fool to interpret this as an agreement to never expand into audio/video in all of perpetuity. Furthermore, Twitter's own trademark filing (since 2007) lists "video and audio" as part of the goods and services provided by their brand. Perhaps this argument should have been made in 2007, or when it was published for opposition (which is basically the USPTO's way of saying 'hey, if you are concerned about this trademark infringing your rights... speak up!') in Feb of 2008 (however no such filing was placed according to TTAB's records), not 2018.

[1] https://www.scribd.com/document/369311229/TWiT-vs-Twitter