Is this possible now?
We would love to see this feature as well 
Would it take a lot of extra work to make this possible, if it’s not already?
Some of our community members are thought leaders or SMEs that run YouTube Live sessions, which is okay (at best) for Q&A and turrrrrible for deeper discussion.
We want to be able to direct users to post their questions to an existing Event Topic (where we’ve used the events plugin) and have the reply window pop up, and ensure that the folks with the questions are posting to the respective SMEs topic.
One of our big value adds to a lot of the folks we’re working with is that we provide a place where they can engage with their users in deeper discussion.
When they do a YouTube or FB live, they are merely STARTING the conversation. Discourse is the perfect tool to CONTINUE the conversation.
If we could simplify the process by having giving a direct URL that people can click, and we can pre-open the reply dialog box, and pre-fill it with some boilerplate text, that would be so helpful!!