Would nine 1MB transactions potentially create havoc on the BitcoinCash network
No, the hard fork also brought new opcodes. Transactions using those new opcodes have already been made, which caused the chains to become separated. If the only change were a block size limit increase, the developers would (?) put a consensus rule that says "The size of the first block after the fork must be bigger than 8 MB.", similar to Bitcoin Cash's first block, after forking the Bitcoin blockchain. "...must be bigger than 1 MB..."

Trivia: Rawpool continued to mine for the old blockchain for one day. More information