Twitter has announced new API access tiers that will be phased in during the coming month – effectively ending free use of the APIs that allow Drafts’ Twitter integrations to work. This includes actions that use the Twitter action step as well as scripted actions that use the Twitter object.
As it stands, the Drafts integrations utilize v1.1 of Twitter’s API - which is being “deprecated.” What, exactly, “deprecated” means is not clear. Might mean Twitter is completely shutting off those APIs. Might mean nothing immediately changes. Hard to tell.
As announced, the new access tiers are a non-starter for continuing direct integration support in Drafts. The “Free” tier would not support the app, the “Basic” tier might, but would cost $100/month, which is not sustainable. It would also mean updating existing implementations to use the v2 API.
On the bright side, I believe it may be possible in the future for individual users who really want Twitter integration to sign up for their own personal Twitter “Free” accounts and use scripted actions to post with their own API keys. Not 100% sure, but seems likely. I was going to try to put together and example for this case, but as of right now you get an error if you try to sign up on Twitter’s Dev site. 
Also, you will still be able to send text from Draft to the official Twitter app via the share action, or URL-based actions that open the Twitter app.
Right at the moment, due to the lack of clarity from Twitter regarding aspects of this transition and its timeline, I’m not going to make any changes in Drafts. I’ll let the existing support ride for now – just don’t be surprised if sometime in the coming months Twitter-related actions start failing. When I know for sure this is a done deal, I’ll add better failure state handling in an update.
Anyway, that’s what we know for now. More news as this shakes out in the coming months.