'will be alerted' is correct and usable in written English.
You can use it to indicate that someone will be notified of something. For example: The emergency responders will be alerted if an intruder is detected.
Viewers will be alerted when product placement is being used.
Dozens of people on our transplant team will be alerted: cardiologists, nurses, anesthesiologists, surgeons, intensivists, perfusionists.
If and when a decision is made, the media will be alerted immediately".
If you are not there, someone will be alerted and be able to call the police.
If the child ventures out of this zone, the parent will be alerted.
Motorists will be alerted to a malfunction by the air bag warning light, she said.
Physical signals will be alerting my brain to stop pedaling.
He needs to take responsibility; else I will be alerting the WWF (4).
You can bet that tomorrow's Amazons, Googles and Facebooks will be alerting — or warning?
Among the probable first steps for investigators will be alerting international authorities and art registries, he said.
Plus, you'll be alerted if they screenshot it, and get sent a copy of what they captured.
