Answer: Hello, @stillnotspamdog!

With regard to your question in question. 

We do actually support COUB, as luck would have it. But it’s very possible something changed on their end that broke our ability to embed their content. How we handle their embeds, on our side, hasn’t changed in several years. One of our engineers would need to dig in on this more, but with time and resources stretched a little thin at the moment, we cannot say for sure when this might be.

🕺🏻You spin me right 'round... 🎶🔊