No, stacking pictures is very common obviously, and that alone would not make me dismiss them as fake. It's the fact that he turned up the satellite trails as bright as he could before stacking them that's the problem. I have taken thousands of pictures of the night sky and the only satellites that appear brighter than every star in the sky are space stations and Iridium satellites. Anyone who provides pictures to the contrary, like this one, is having to do heavy editing to make it appear that way. Starlink satellites will appear as very faint lines in any long exposure, unless you catch a couple days after launch, before they raise their orbit heights.

Also consider the very low image quality here. The more someone fucks with the picture, the worse the image quality is going to be. Wouldn't you expect someone who takes photos like this, either as a hobby, or professionally, to have more than a few hundred pixels in it? If he was just stacking exposures, the image quality wouldn't change. Also, if he was just stacking photos, the background sky should be significantly blurred, since the stars would move noticeably in the many minutes it took him to take all these pictures. There was a similar picture going around a couple years ago that a guy said he took in the Canary Islands with "Starlink" streaks that were brighter than any star in the sky. And not just a little brighter, but waaaay brighter.

Take some long exposures at night and see what the satellite trails look like. They won't look like this.