Basically reiterating what everyone else is saying. I'm truly puzzled. From the start, it's very odd for JFK grandkids to be singing a song on YouTube, they are obviously not professional singers. But a song about Timber, possibly reference to Timber Wolf. Another oddness is the number of grandkids. JFK only has 3 grandkids that I know of, all children of Caroline:

Rose Kennedy Schlossberg

Tatiana Celia Kennedy Schlossberg

John Bouvier Kennedy Schlossberg

However, there are at least 8 kids in this video, unless some are the same people wearing different outfits and I'm not recognizing them. JFK and Jackie had Caroline and Jr who lived to adulthood, two others, Arabella and Patrick died as infants. Jr. died before having children. So who are the other 5 grandkids of JFK in this video?

1) young man with gray earphones, gray shirt, possibly John/Jack Schlossberg, hair a lot like Jr., online pics of him strongly favor Jr.

2) young man black over-ear headset, long sleeve pullover over black shirt

3) girl, hair pulled back, gray short sleeve, button up shirt

4) pretty girl, wispy curls seen in back, elephant trunk earrings, white sweater top, talks odd, Tatiana Celia Kennedy Schlossberg

5) boy, medium brown hair, elephant trunk earphones, blue zip up shirt

6) girl, black hair, black/white check shirt, Rose Kennedy Schlossbery

7) boy, short beard/mustache, white t-shirt, looks a lot like Jr.

8) girl dark hair pulled back with him red t-shirt, smile looks a lot like Carolyn B.

4 boys, 4 girls, who are their parents? Coupled with the video ending in YesQ, there is some serious "mess with your brain" stuff going on here.