It seems that this update process when activated from within Studio (i.e. heeding the orange notification and then downloading and installing) goes through the motions and then will ask you to restart your PC. However, two things happen: 1) old Studio gets deleted, and 2) newer Studio is not actually installed/updated and you get nothing, the icons disappear, etc. So what one is supposed to do is, once one knows, an update is available via notification? Get out of Studio, get the .zip or .exe update file somewhere else and follow the instructions. In other words, download the update .zip or .exe file manually.
This has happened before:
This is a bug in the update process, I believe.