Hunh?
The volume of standing live S. Sempervirens (coastal redwood) has never been higher in recorded history. As for the other Sequoia (giganteum, giant redwood), that is not what you are buying at the lumberyard.
I think that BOYLER above is referring to a recent news report that the NPS will be removing 1000s of trees in Sequoia Natl Park to reduce the fire danger after last season's fire endangered the iconic giant RWs. I suspect most of those trees to be removed are other species.
The Big Problem is that natural fires, and seasonal burns set by natives have been disallowed here for 230 years. The coastal rainforest where I live, and where coastal RWs come from has become overgrown and poorly managed.
You are right that the sapwood of a RW tree will get powder-post beetles in it within 2 years after it is cut, in my area.