To be fair the opposite has happened.
Indeed. Scratches was removed from GOG about two weeks after it was removed from Steam. Also, Chronicles of Riddick was removed from Steam about 4 years ago, but it's still here. There are other examples like Neverwinter Nights 2.
The Void was removed from Steam quite a while ago and it's still here on GOG. *knock on wood*
I don't think that The Void is actually in danger of being removed from here. On Steam, it was removed by the developers because they had troubles with one of their publishers, ND Games and wanted to take control of the distribution back from them. The game was brought to GOG by a different publisher, which is why it doesn't seem to have affected anything so far.