So to answer your question and not fill more input on the way things have been handled (or not handled) prior to patching...
Stop putting out codes.
The chance of getting one is slim at the very best. If you're a European or OCE-oriented player, there's even less chance since it is now moving towards Midnight and tomorrow, is friday unless you had noticed. People work tomorrow.
Those that doesn't get the codes will feel irritated, in a way as you say "Salt". They tried, didn't get it, but they still somehow feel entitled to it (they are not but offering the chance, causes this).
It is only making it worse for the majority of players.
Either give everyone or no one. We are "all" affected by this issue, I'm sure you can understand that - and giving only a portion of people a chance at these attempted plasters on the wound, you're only making it worse.
What is to stop someone from possibly (if daaaamn lucky or quick) to get more than 1 code, during the entire so-called "Rain"? Nothing? I figured as much.
So...
Stop it.
Either give everyone said pets (like you do with the 8th-pet droids etc) and/or the CC (as an excuse for your (general term) competense and QA-fail) or don't give/offer anyone these things.
How come that these codes are mentioned/showed up now, aprox 6 hours after initial down, 4 hours after the "Opsie!"-takedown? Why didn't they come earlier, when it was EU-primetime?
Yes I am a EU-player so I am biased - please do acknowledge and accept that.
Oh and while I hopefully have your attention, could you please check into the Collections Unlock issue with the Stronghold Defender-weapons/items? It's been 1½ year since their release - can still not Unlock them (have filed 3 Bugs/Tickets on it).