Can you upload Udemy preview videos on YouTube?

I’ve read that you shouldn’t post udemy course videos for free elsewhere if you are charging for them on udemy. However, say I have a few videos in a udemy course that are public, as in any user can watch the videos as a preview for the course and hopefully entice them to buy the rest of course. Would I be able to post those specific videos on YouTube as they are technically free on Udemy as well since users do not need to pay or buy the entire course to watch them and this will aid in driving YouTube traffic to buy the rest of the course as well, the same way the previews on Udemy will push the users to buy the course.

I have not finished making all the course videos but I’d also like to asses the demand by posting such a video on YouTube before creating the rest of the videos.