This was true for JEREMIAH; not everyone has been ordained to be a prophet to the nations. I do believe that in situations and with people that are key to God's plans, He will intervene in ways that make sure His specific purposes/will are accomplished. The conversion of the Apostle Paul looks like a case of this. But though God made sure Paul got saved, where it almost looks like his free will was overridden, Paul himself later writes that it was possible he, too, could lose his salvation:
"But I chastise my body, and bring it into subjection: lest perhaps, when I have preached to others, I myself should become a castaway."
–1 Corinthians 9:27
https://www.biblegateway.com/passage/?search=1%20Corinthians%209:27&version=DRA