I saw a good explanation on Twitter about payment processors and charge backs that can explain a lot of this. Not happy about it, but it does make sense.

I'm not as clear on taking away the ability to gift some things period, like mounts and minions, unless the Mogstation isn't connected to the system that stores the information about what someone has, like you can see on the Lodestone. But to that I would say that I hope this is temporary and they're working on a fix there because taking away the more popularly gifted items just seems to be a very odd choice.