You neglect that THEY turn off your water heater - for now.
What happens when they decide during peak hours to turn it off. When you’ve just come home from a dirty job and want to clean off, or when you wake up for your 9-5 job and want to shower?
I’ll bet a dollar to a donut, the fine print read they could turn it off whenever they wanted.
They should be able to turn off your wh during peak.