Because I'm not religious I don't find this anymore offensive than the theft of any article.
I once saw a doco. about the funeral industry and about how a family complained about a terrible smell in the family crypt.
Turned out that the coffin is lined with zinc so that the putrescent body fluids don't leak out through the wood.
This time the brittle zinc had cracked and the parlor had to replace it.
This made me google " copper lined casket " and yes all sorts of metals are advertised and promoted with their individual advantages (and prices ) for casket lining. Buried coffins are also metal lined.
I'm sure that the dead will be dug up for coffin salvage in the future.