To answer your topic question Does pamac delay updates from the AUR
No - pamac does not delay updates.
Because pamac does not query AUR directly, yay does.
It uses a manjaro CDN which a some intervals will download the metadata using the api provided by AUR.
The reason is due to the popularity of pamac across Arch based distributions which causes a heavy load on AUR api.
Search the forum if you want to know the details.
Start with [Need-To-Know] About Manjaro and AUR