I looked it up on the internet:
http://www.pcworld.com/article/3008227/windows/windows-10-november-update-apparently-deleting-some-third-party-programs.html
http://www.zinstall.com/how-to/how-to-upgrade-to-windows-10-without-losing-your-programs-and-files

and others. Apparently it is true.
I haven't missed anything so far, and since I saved my user folders before upgrading additionally to the backup, the upgrade couldn't delete anything I wanted to keep. If it did, I will find it again, since I have a copy of the state before the upgrade.

I use their OS, but since Microsoft every now and then wipes out users' work*) by changing this and that, I don't trust them. In addition to my weekly backups I save downloads asap to external drives.



*) Example: On Windows 2000 and XP I did enter properties for many files (like pdf and others) that showed up in certain columns in the Windows Explorer. MS changed some standards and claims that the other software companies didn't follow that change.

Desktop; i7-2600k, 8 GB mem., Win 10 Pro, BIAB 2017; RB 2017 - latest build
Laptop: i5-2410M, 4 GB mem, Win 10 Pro, BIAB 2017; RB 2017 - latest build