Dear GOG,
A the title states, I see user reviews disappearing.
Not the irrelevant ones, not the "offensive" ones, just some old ones.
Is there a good reason for this?
This is not the first time I seek support about user reviews, but for me, they are the main factor
when I decide wheter I buy a game or not.
I' probably wont purchase anything until I get a reasonable aswer.
Thank you.

Maybe reviews also suffer from this issue?

I can only speak for my reviews now missing - but if mine are gone so can be others' - under these titles:
Hugo trilogy
Thunderscape
Wizardry 8
Entomorph

Might have been more, but I distinctly remember writing about these.

Pretty hilariously, that link reveals yet another bug. If a thread has some posts deleted, linking to a specific post takes you to the page the post would have been on if not for the missing posts. I followed your link but had to go onto the previous page to find the post you were actually linking to. Thanks GOG!

Were you logged in when you visited the link?

When I wasn't logged into my GOG account, the same problem you experienced happened. It brought me to the top of the page after the page that the post is really on. But after I logged in, I tried the link again and it brought me to the correct page AND to the correct position of the linked post (post number 24459).

Yup, logged in the entire time. I imagine it depends on how many posts you have set per page, I have it set to the maximum (50). I'm guessing you have it set to something different and the post was on the page that the forum expected it to be.

Example:
There is a topic with 100 posts, minus one that was deleted for spam (post 49).
Someone posts a link to post 51. If I follow the link, it takes me to page 2, but post 51 isn't on page 2 any more.
If someone with the setting of 40 posts per page clicks the link, they get taken to page 2 and the post is there (because the boundary between pages is between posts 40 and 41 for them.

I understand.

(Strangely, the number of posts per page while NOT logged in is 15, which isn't an available option for people who are logged in. We can choose to show 10, 20, 30, 40, or 50 posts per page, but not 15.)

It's been that way like... forever ;-)

For someone to be as long here as you it's strange to never have noticed it.

It's not new to me, it was just amusing that HSL was linking to a post about a GOG bug but was thwarted by a GOG bug.
Having said that, I'd never thought about the cause of this particular bug before because I don't encounter it very often. It only crops up on X number of posts per page, X being the number of posts removed. I don't hang around in the megathreads that have been hit with spam loads of times so the bug seems pretty rare to me.