You are correct the parent is not referring to deflation - just slowing inflation. However Bitcoin is strongly strongly deflationary because any random walk down the timeline leads to 100% of coins lost. Due to human error, act of God and chance. In its first 12 years, give or take 20% of all Bitcoins were lost in spite of, what, 80% of all coins being generated. Thats an annualized deflation rate of 2%.