Locaha's comment still doesn't really make sense. Senescence is a specific mechanism that makes you more susceptible to cancer and heart disease, among other things. Curing cancer and heart disease won't cure senescence, though curing cancer probably would help. Curing senescence should cause a clear decrease in cancer and heart disease when you improve the ability of human bodies to repair themselves.
To cure cancer and heart disease (as opposed to postponing death caused by cancer and heart disease) you would have to stop senescence. As long as senescence continues, heart disease and cancer will occur.
When viewed in this light, you can see that Locaha's comment makes perfect sense.
Google's announcement, Time magazine rather sensationalist headline.
In any case, it's nice to know that Google set its sights to "challenge ... aging and associated diseases". Apple's Tim Cook:
For too many of our friends and family, life has been cut short or the quality of their life is too often lacking. Art is one of the crazy ones who thinks it doesn’t have to be this way.
One more step towards "world optimization".