That's a false analogy.

CD's are not going to become popular again to listen to music because "pendulums swing".

When a trend is clearly going toward increased comfort or clear progress, there is only one direction that the trend is going.

I argue that statically typed languages are headed in that direction and that in ten, twenty years from now, dynamically typed languages will be looked at as "something that seemed like a good idea at the time".

"Increased comfort" and "clear progress" are subjective measures about which people may disagree (to whit, I disagree).

I argue that in ten or twenty years from now, we will have great tools in dynamic languages to express constraints when needed, without requiring proofs.

These are opinions, not facts.

Is there anything to capture (dev-)runtime data & generate specs from that as a starting point?

super. thanks