Good morning, yes, its an excellent question. I believe we had 10-12 Ylands during the early access stage and I know they were difficult to find. With the changes that came from the release the overall map is smaller and the number of Ylands is fewer, making them easier to find. I did a video back on October 9th that went over the highlights of the Dev Diaries 95, 96, 97 & 98 where they talked about the changes to exploration. Diary 98 talks about the reduction in the number of Ylands and I think it was mentioned somewhere that it would be 8-9 Ylands but I have not found a definitive on that this morning. Be cautious of any data you find online that was posted before the release, a lot has changed ?
Have fun exploring!