They were announced via the Dev alerts. Gaia has long recommended everyone have them active, so if you deactivated the Dev Alerts, well, that's your fault, not theirs. They made a point in telling the community.
Sponsors pay Gaia far more than users and your "free" GC was paid for via a sponsor. The cash wasn't free, someone was paying for it, it just wasn't you. And if the sponsor pulls out it's not beneficial, financially, to keep giving out something that *should* be paid for.
That said, I'm sure Blue Noodle brought in a nice amount of money for Gaia since virtually everyone used it. So they are probably looking for a substitute.