The last few days I observe recently updated projects on top of the list in the 'Recent projects' list that I certainly did not update.
Nothing actually seems to have changed in such projects, but it's a annoying that in my list I don't see the projects I updated lately on the top of the list.
For example a project I certainly did not edit for months.
[Addendum] It looks like every time anyone views/opens a project, its updated state changes. So 'updated' actually seems to mean: 'last viewed' or 'last opened'