This is true, but he is still 5 years older than she is and so he likely has an average 5 fewer years left to live than she does; probably more than that, considering the differences in male and female life expectancy.
As enjoyable as retirement can very frequently be, the whole reason why people retire is because, to put it bluntly, their abilities are starting to slow down - before long rendering them incapable of doing paid work reliably - and will continue doing so until they die.
Without wanting to sound pessimistic, you have to be realistic and accept the twin facts that retirement is the (hopefully very long and healthy) happy period of time after your (employed) work has all finished and also the less happy period of time before you die.
On the surface of it, it does sound like he's being insensitive, but it may also be a defence mechanism whereby he realises that he isn't getting any younger and this is a marker of the fact that his remaining time is slowly dwindling - much faster than that of his DW.
Granted 67 isn't especially old, but some people in/approaching their later years start to feel a bit left behind by the world and aware of their limitations; and crowing about their retirement and no longer having to go out to work (and/or their wisdom and experience in life) is their trump card that they will often play, realising that, on balance, they don't otherwise hold an especially good hand in life anymore when compared to a young adult who has it all still to come.