Well....
It certainly is possible that the work that has been done to create a "new" HC-110 has been oriented toward making it easier to measure and pour as well as easier to manufacture in more locations than just the previous Tetenal line. Maybe they came up with a way to ensure the same development performance and excellent longevity with a less viscous version.
You know, "New and Improved!"
And as for "best before" dates, these may be as much a reflection of what the ISO certifications require as anything else.
With the old HC-110, it was the packaging that was most vulnerable to failure.
It certainly is possible that the work that has been done to create a "new" HC-110 has been oriented toward making it easier to measure and pour as well as easier to manufacture in more locations than just the previous Tetenal line. Maybe they came up with a way to ensure the same development performance and excellent longevity with a less viscous version.
You know, "New and Improved!"

And as for "best before" dates, these may be as much a reflection of what the ISO certifications require as anything else.
With the old HC-110, it was the packaging that was most vulnerable to failure.