Basically, we are all aware that the views are restored and that is why we always customize them through inheritance (Studio or development). 

But it appears that other things such as "user groups, access rights, etc." (copy/paste from the Support Team, the "etc." should be clarified) are restored too. We noticed it could affect the financial reports too and probably other standard records coming with the app/module.

For example, if you simply rename a user group, a manual (sometimes asked by the Technical Team after a bug fix) or an automatic update (quite rare but could happen, randomly in October/November) of the app/module could revert your changes. And it will probably explode when the database will be upgraded from version X.0 to Y.0.