you are absolutely right. If you look at these inevitable trends it is absolutely counterintuitive to lower the retirement age. It also seems very inconsistent with previous policies which raised it to 67 years.
However, I think we need to overcome the notion of "retiring" more fundamentally. The current debate is very much driven by a 20th century mindset which assumes that people have to do for many years an unpleasant job until they earned their retirement. Today, most people actually enjoy their work and (if they are not involved in manual work) could do it well beyond the traditional retirement age. If we all paid a little more attention to the quality of management then you could get to a situation that people actually don't want to retire. They may work less at a certain age but still remain engaged.