Towards the end, the company also mentions direct messages:
And we haven’t forgotten about Direct Messages. We have several updates coming that will make it easy to take a public conversation private. The first of these was announced today and will begin rolling out next week: the ability to share and discuss Tweets natively and privately via Direct Messages. Stay tuned!
“We haven't forgotten” sounds like a curious statement from a company that, for some reason, decided to disallow sharing URLs in direct messages last year and never bothered to fix them. It sounds like Twitter will bring back the ability to discuss individual tweets in DMs, but, frankly, it makes no sense that people who follow each other shouldn't be able to exchange any URL privately.