Yes, they did some weird stuff in the past that technically can be considered a retraction. For example, they changed the Goblin Leader bestiary (kind of pointless, but still a positive thing that was made for the community). They also did other changes as minor adjusts on monsters experience (I think two years ago they changed a bit the experience of library monsters). They also changed the whole "region spawn boost" mechanic since the implementation of it. The boosted creature of the day had a bizarre bug that Cipsoft only made the correction several time after the implementation of it, even after several customers denouncing it.
Got this link from the user Fire_Draggon here regarding the library changes and later reversion:
News about the library nerf: https://www.tibia.com/news/?subtopic=newsarchive&id=4802
News about the retraction of the aforementioned library nerf: https://www.tibia.com/news/?subtopic=newsarchive&id=4904
I couldn't find the exact patch where they changed the Goblin Leader bestiary, but it was probably during January of 2019!
But, speaking about the current patch, I think that they will eventually change the experience of the monsters due to the absurd nerf on some mobs.
The whole idea of reducing loot value from monsters is great! I am actually very happy about that. Excellent news for the Tibia economy! But the experience nerf was poorly done. Fury and Grimleech experience is ridiculous now. Not only that, it is beyond me that we cannot receive a updated list with all loot and experience changes made. Only a vague list with the name if several mobs on it.
TLDR: Cipsoft retracted from changes made in the past, and we certainly gonna see more of such actions in the future.