EntranceJew posted:

I haven't seen this stated elsewhere, so:
If you want to post a video to YouTube later from Twitch, you should make at least one highlight from the stream session.

Based on recent changes in policy, in addition to having to tick the option to keep past recordings in your settings, unless you create a highlight from a stream it will not save it. Once you create a highlight, it will signal for Twitch to keep the full stream that it originated from. This is the only way to keep a Twitch recording. Please keep in mind that Twitch cannot upload videos greater than 2 hours to YouTube so if you intend to wholesale push recordings to YouTube you should chunk it into 2 hour sections.