Yes, that is right the population growth rate started declining more than half a century ago. In 1962 the growth rate peaked at 2.2% and has halved since then: https://ourworldindata.org/world-population-growth#the-globa...

The projections from different research teams differ in when they expect the population population to peak. IIASA suggests what you say, the UN expects it later. I looked at the different projections (and what is behind the differences) here https://ourworldindata.org/peak-child