There’s a fair bit known about life spans in general, yet more or less nothing about Worgen.
Sadly so, even.
However, one can absolutely speculate given that Genn appears fairly able despite his age. Then again, with the Reclamation of Gilneas he passes the care of the kingdom to Tess.
Him more or less suggesting the world is changing faster than he can keep up with feels and reads like a poetic reference to him finally reflecting upon his age and slowing down.
Yeah, Tess is the rightful heir of the throne, I remember playing through the questline. I kept asking myself what’s the future of my people, slowly but surely we’ll let the curse die off, or keeping the identity with freedom of choice somewhat like Tess refused to be affected by the curse.
Worgen are a druidic form. Specifically an alternate version of the feral form. A druidic form doesn’t enhance their lifespan. The long lived worgen we see in comics are cursed night elves, who have very long lives, even after giving up immortality.
Of course it could be argued that the ferocity of the worgen boosts the body to function better for longer as we see with Genn. But there is no official lore on this.
My head canon is that they would be a bit like the Numenorians from LotR, where a worgen in his 80’s is considered mature but not old.