New 18 year old voters have always been more left wing and 90 year old conservatives have always been falling off the perch. That's not news.
The analysis does not account for people becoming more likely to vote Conservative as they age, but this traditional trend has begun to break down among younger generations.
This is the real story. This is what's standing on the party's oxygen tube. The supply of new conservatives has broken down. It turns out that people don't get more conservative as they age, they get more conservative as they gain wealth - and today's 30 and 40 year olds aren't.