Yes, as far as I know your information is correct in general.
Lithium Ion batteries get strained if they are charged at extreme conditions (I think due to corrosion). “Extreme conditions” include low and high battery levels. So keeping the charge between 40 and 80 percent helps to increase lifespan of the battery.
However I’m not sure about the monthly discharge. That sounds like a trick to avoid a memory effect. Lithium Ion batteries don’t suffer from memory effect, though. So I don’t know why that would be necessary.
I’m not expert, though, and there are several (contradicting) guides floating around the internet.