I know the feeling. I've been waiting for Ilambris for a while, but that was the first one they brought out in 2018 and it hasn't been seen since.
This is actually the first time we've seen arms packs other than Iceheart come back. I was hoping that they would have brought more than just the four, but at least they were seen again. Evidently we need to wait until next Undaunted event next year to see another set return for a weekend.
I would like them to start rereleasing these packs every so often, like maybe a weekend every 4-5 weeks or so.