As I experienced, all the reviews for your course will NOT appear in the landing page. Only a few ones selected by Udemy's algorithm will. They will surely count while calculating your course's overall rating though!
If your course reviews are not appearing, it may be because they got caught on our Spam filter. This filter is designed to make sure the ratings and reviews on each course represent the honest opinions of genuine, engaged students. If it detects that a rating is artificial in any way (i.e. from a bot, a script, or a biased source) it will prevent that review from displaying.
Also, if you need help on how to use Udemy, I recommend reading the following article: Teaching on Udemy: F.A.Q. For any other questions, feel free to ask here and we'll be happy to help! 🙂