There wouldn’t be any reason to remove her implants if she were buried.
If she were cremated, I’m not sure. I know that oftentimes non-combustable material is put in the furnace (I’ve read that sometimes people are cremated in metal coffins: they have to peel back the top, or the corpse is just “baked.”) There might be some sort of EPA regulation regarding burning silicone implants, but I doubt if they would bother to remove them otherwise.
Yes, I’m sure that aliens, or archaeologists in the future will find a skeleton or two with odd silicone lumbs on the ribcage. I doubt they will be much confused if our records survive, but if they don’t, perhaps they will use the archaeological catch-all: “They were used for ceremonial purposes. Probably connected with a fertility rite.”
There was a case on the HBO show “Autopsy” wherein a human skeleton was found with what looked like “two jellyfish” resting on the rib cage. They were found to be silicon implants which leaked their fluid over time. The body was identified by the serial number on the implants and the murderer was eventually caught.