Hey dude, I just downloaded the version 6.1.0 for mc 1.12.2 and I just realised that most of the features like the crown, toys, the personallity of the villagers and a lot of other features are no longer in game, what happen? They are gone forever?

From what I've understood by looking at the mod over the past, yes, as the mod got updated, it's lost several features.
The version I originally had for example had the crystal ball, kinda miss that feature, and how npcs would speak to you in chat, they had their personalities as well, and a config feature that could make them unkillable so that a random zombie siege or other hostile mobs wouldn't wipe out a village while you was gone.

Current one is even missing villager progression, they won't reproduce any more on their own like they used to in the past versions.

As to why it lost a lot of these features, supposedly the mod was re-made from scratch.

EDIT- If I remember though, someone has recently made a mod add-on to MCA that brought back stuff like the crowns/etc.

Is that add-on mod available for 1.12.2? I feel so sad because the last update for comes alive was in 2019 :(
I hope they come back one day or something

Mod's name is "MCA Old Life" on Curseforge

Yet to try it myself, but it says "Adds removed items from MCA 1.7.10 and 1.5.2"
seems to just add back in the crowns and molded diamonds.
If you're wanting the generated structures via the crystal ball, I'd say run an older copy of MCA on a throwaway world,
and use worldedit to make some schematics, I did this to create a MCA structure village on my server.

On another note, if I understood coding more, I'd fix a few of MCA's issues myself, namely the whole villagers having the wrong profession names in their names.