Do we want answers with embedded youtube videos or is a link to the Video(s) preferred? Any rule for that? Just found metas about "Video only answers".
It's up to personal preference. Some prefer to use a link to YouTube as a regular site link like so. Others prefer to embed them directly.
I think if it's only one or two videos, having them embedded is fine. if you're linking more than a couple of videos, then use the link option to link them properly to avoid your answer from getting too big.
Also remember that a YouTube video should not be an answer by itself. If the video is taken down, your answer should be able to stand on its own without it.