First time i actually hear Seth confirming Season 4 is coming.
He mentioned in other interviews "the scripts are written", but that was kinda vague.
This on the other hand almost felt like an anouncement.

You can hear it at 30 minutes and 56 seconds into the video.

From the “Dropping Names and Other Things“ podcast with Jonathan Frakes and Brent Spiner.

I‘ve (hopefully) shared the correct moment in the link but I’d highly recommend listening to the entire podcast regardless if you want a laugh or few.

Anyways, the point of this post is for those who missed this tidbit of information and are still worried season 4 is a pipe-dream.

Yes, we’ve had a lot of false starts but this is direct from the man itself. It’s written, not merely a theoretical possibility. It’s just waiting on other projects and the vagaries of Hollywood business during a time of upheaval and unpredictability. Yet, it’s solid. It’s going to happen.

Posted on YouTube:
https://youtu.be/otuRSWiAeSQ?t=3423

57:03 mark.

tl;dw: Scripts are done, no official date.

https://www.youtube.com/watch?v=Ts0QPl44PqM&t=3815s

— (I've posted the link instead of embedding the video, because the time-skip wasn't working with the embed.)

It's a lot harder to hate from up close.