I... don't think I have ever seen it do that automatically unless I missed some steps in the installation guide...? most of the time I just created the partitions I needed. I did a quick CTRL + F on tmpfs or tmp but not seeing anything...
Anyhow, I don't see on my desktop which still has Arch Linux installed which I want to move to KDE Neon but extremely lazy when you have an immense backup to do...