I had never seen the number of deaths compared to the number of Christian conversions until I encountered this link. There are lots of assumptions built into such a broad analysis. We never know for certain what the future will bring. What he wrote reflects other statistics.
The link author has planted Protestant churches. He says it is an exciting thing to start a church. Christian sites discuss planting churches all the time and imply it is the solution to falling Christian numbers.
The author points out, however, that planting churches will not reverse the downward trend. There are about 300,000 Protestant churches in the U. S. If the average net increase of non church people (not stolen from other churches) per church was two each year, which he says is not an unreasonable number, this would increase the number of Christians by 600,000. This raw number appears large.
However, out of the U.S. population of 320 million, about 2.6 million die each year. If half of these deaths, largely among the most religious group, the elderly, it would mean a loss of 1.3 million. This makes the hypothetical 600,000 added too small for a sustainable total number of Christians. New start up churches help offset this loss but their numbers are small.
The young pastor is enthusiastic in his desire to find a solution to this problem. He knows planting churches cannot grow numbers enough to reverse the trend.
To me the trend can only be reversed by better alignment of church values with societal values.