I'm going to try and stop this back and forth debate
At the end of the day, templates being updated has been troublesome. We're trying an experiment to see how things go without updating them.
IMO, Templates very, very rarely change and I don't see that changing all that much in the future, and the number of templates that needed to be set to not update was very steadily increasing.
But, if this change in 6.10 proves to be troublesome again then we'll revisit the whole thing again and try a different solution. In the meantime, we're not putting in updates to the templates...