I won't disagree that some of the events have had some questionable management as of late.
I personally think there's a lot of issues with the Covid era. Back before 2020, codes were just as usual given to shops, and the main purpose of these codes was to attract potential buyers, nothing more.
"Here kid, here's your shiny new Rockruff, by the way what do you think of the fancy stuff on the desk?"
It's really standard marketing and nothing more.
HOWEVER when Covid happened and literally everything moved online, it's pretty obvious lot of companies were not quite prepared for the online-only distribution and moreso while still trying to only keep their partners.
Phisically going to Gamestop for example would usually deter people from just trying to get to multiple GS just to get multiple codes... but, online requests are different, which is why modern ones just go out of stock super fast, cause nothing is stopping us from requesting them or even multiple of them as soon as we can't get one istantly from the tecnically appropriate method.
Running out of code cards sounds like
R_N 's option 1/2 are the most likely. I assume they're only given X codes and if the store or TPCI do not expect a large amount of requests, it's easy for them to run out.
I don't know what happened with the whole newsletter thing as I'm from EU and we basically always had gamestop as distributor here, definitely something did go wrong, but once more... I'm afraid this is just another case of TPCI barely caring of what happens with rest of the planet and only having interest in making sure their local distribution goes right.