Platform independent state files should be signed by whomever is claiming they are a valid record of the blockchain state, and/or potentially signed by consensus witnesses, possibly with the valid state checksum committed to the chain itself (which process would then constitute signing by consensus witnesses to the extent the recorded commitment is validated).

Just throwing these files around without accountability is dangerous as it leaves open the potential of everyone being too cheap or lazy to do their own verification, just copying the file and leaving the hard work to "someone else", with a malicious or accidentally incorrect state file spreading widely through mere replication. Comparing checksums doesn't help with that.