I would think they should definitely reimburse those gems.
Marti Claw will probably be around after the goal to breed it expires, and this one should be too. We don't actually know that the Giraffe will ever be limited. That feels overly optimistic, though... but I would say it will probably be around for a month, and the Marti Claw as well, so there is time to work on them... at least they share one element, so breeding dark-earth-electric will work. I was doing this anyway as I still don't have a Gargolem. That would be a really nice fail for me... however, I may just buy it for the 200 gems if I don't get it this weekend.