youtube links should be accompanied by links to alternative front ends like piped.video for those who are yt-averse, but that it is okay for the canonical yt link to be included for those who wish to interact with the poster's channel. I think I have a preference for the piped.video link to be the post link and for yt links to be included in the body, but am fine with peertube links being the post link.
If there are accompanying documents, such as the slide deck I'll be using tomorrow evening, those should also be linked - it's my feeling that posts of this nature should be viewed as resources for the community. In my particular case, I'm happy to share both the shared file in my gdrive but also a .pptx file on an accessible filesharing site (especially if there is a consensus on which are most preferable from privacy and accessibility standpoints).
It is an expectation that folks posting their channels or videos engage with the community in other ways as well and are not spammy