Just because it's not provable or falsifiable doesn't make it nonsense - just a theory - albeit in this case a weak one.
Many untestable, unprovable theories in the past were considered nonsense and later proven true.
Many untestable, unprovable theories in the past were considered nonsense and later proven true.
I think the way you're using the word "theory" here dilutes its technical meaning. More accurate to call it speculation or philosophizing.