This is a somewhat common question these days, it seems. Here’s another post from just 5 days ago.
Are there incorrect vocab words on WK? How best to supplement vocab with other sources?
Yes, not all the words WK teaches are commonly used. The purpose of WK is to teach kanji. The vocab you learn from WK are used only to help you learn their kanji. You can’t always find three unique words for each new kanji you learn that doesn’t use kanji you have yet to learn, so it follows that less common words are going to be chosen.