These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.01 s (backtrack: 0/20).

[ebuild  N     ] gui-libs/eglexternalplatform-1.2.1::gentoo  11 KiB
[ebuild  N     ] dev-util/wayland-scanner-1.26.0::gentoo  599 KiB
[ebuild  N     ] dev-libs/wayland-1.26.0::gentoo  USE="-doc (-selinux) -test" 0 KiB
[ebuild  N     ] dev-libs/wayland-protocols-1.49::gentoo  USE="-test" 148 KiB
[ebuild  N     ] gui-libs/egl-wayland-1.1.23::gentoo  78 KiB

Total: 5 packages (5 new), Size of downloads: 834 KiB