what periods of time were considered decent by all

A good question - I think you'd have to define "decent" and "all" before we could hazard a guess though.

And agree on the morals of the universe, I think that was an artifact of the time it was originally concieved. The more common version I see omits "morals" and just says "the arc of the universe" which isn't so jarring. In other words the morals either are omitted from the concept or their inclusion is implicit in whatever morals exist in the universe to the listener - which in our case would be none, but others may see some.

This opinion piece has a similar view that moral isn't useful here and "justice" is only what we actively work to make it. IMO that's an unfortunate countering of the phrase's popularity and sort of robs it of some of it's inherent optimism by demonizing 'magical thinking' - which is a whole other bag of worms I have no intention of opening up.

I prefer the sort of basic idea that the unknowable is geared to good, we just have to see it. I disagree that that's 'magical thinking' in the pejorative, I just think that it's not wrong. Context is all of course, and in the largest context we can concieve, good is either the default or it's moot to the point that it may as well be for what we can know now.