The whole idea behind the long-term warning project is that it should preserve its semiosis long after every other trace of its originating civilization has ceased to be detectable, so including maintenance in the remit would violate the fundamental premise.

(I don't think the premise is all that well founded, hence my original comment.)

Separately, the material in the Goiânia radiotherapy device was cesium-137, which has about a 30-year half-life, so any sample of given activity today would see that activity halved about 330 times over ten thousand years. I think it would take a much larger sample than typically found in medical equipment to remain hazardous at the end of that time! The long-term warning project has a somewhat narrower domain.