ITW means that malware authors actively use it.

It’s not possible to detect any “possibly malicious line” in BAT files. While some malicious scripts may try to destroy user’s data, it’s certainly possible that someone else uses BAT files to format new hard drives, without any malicious intent - and it’s the same line.
So no, your file won’t help protecting against real-world malware in any way.

If you wish to become a malware author - start to publish these scripts and they start to be used in malware, their detection will be added.