I believe most temperatures communicated on the internet are breeding temperatures. This holds for al lot of fish species, not just Dario.
I assume breeding is associated with welfare. Hence, if you keep fish at those temperatures, it serves their wellbeing.
But breeding is not an indication of welfare for many species. We keep most fish at too high and too constant temperatures. There are a few studies that support this.
So yes, I am mimicking their natural environment to a certain degree that is. I see different behaviours in different seasons. How cool is that.
And yes, the male doesn't tolerate the female once breeding occurs. I've never seen them prey on their offspring. I've never seen broodcare either.