Im assuming the same thing is happening when HoT came out 2 years ago.. here is a post that a dev said regarding this issue.
https://forum-en.gw2archive.eu/forum/game/hot/72-hours-to-get-my-gems/first#post5376579
“Over the last week we have seen an increased fraud purchase attempt rate for our Heart of Thorns Ultimate edition. Because of this increased fraudulent attempt rate, gem delivery for Heart of Thorns Ultimate may be delayed up to 72 hours after purchase.”