XDG specification section outdated?
The Cursor themes#XDG specification section refers to default theme but I cannot find any mention of such theme other than icon-theme-spec changelog from Version 0.6, 2 December 2002, which states “Renamed the default theme hicolor.” —Jtojnar (talk) 15:04, 18 September 2019 (UTC)
Wayland (sway) cursor change
On sway lxappearance didn't change the cursor in all applications for me. In firefox, waybar and gnome-terminal (all gtk3 applications, I believe) the cursor stayed the same. I had to run
gsettings set org.gnome.desktop.interface cursor-theme cursor_theme_name
to change the cursor in those applications.