So, I was checking out the sales and saw this, see attachment.

What's going on?
It says Cyberpunk 2077 has 4 reviews and apparently has 5 stars. But when I click on it, it has 1207 pages of reviews, starting with 1 to 3 star reviews.

What's going GOG/CD Project Red?

This doesn't happen only to cyberpunk but other games as well. It started from 2020 If I remember correctly and hasn't been fixed since then. If you want to check reviews always check the store page and not the list. Also Cyberpunk has received a lot of patches since the initial release and is in a way better condition then it was so if you are interested don't forget to check the recent reviews.

CDPR has nothing to do with it. And those old promo pages have some long-unfixed bugs (like lots of the site, not least the forums).
Don't ascribe to malice or conspiracy that which can be adequately explained by incompetence or apathy. ;)

I guess the easiest thing to do when something doesn't appear to look right, is to scream...

1) Who looks at the number of reviews?
2) Did you actually expect CP2077 to only have 4 votes/reviews?

I guess this is a similar problem to the wishlist. Over there, it's got a 5-star rating though in the store it's sitting at 3.7 stars. As mentioned above, this affects multiple games. It also sometimes shows a lower or no rating, so it looks like a site bug rather than an attempt to deceive.
For what it's worth, I reported the latter issue to support ages ago, but as expected, nothing's been done about it. Steam has a better review system, showing you at a glace how a game was rated recently, and how it was rated overall. It's also ultimately more helpful to have Recommend/Do not recommend type reviews.