This isn't true at all. The name "Sprint" wasn't chosen until the 70s and the initial business was alternative long-distance carrier, not a railway cell phone.
See: https://www.battlecreekenquirer.com/story/news/2022/05/23/je...
See: https://www.battlecreekenquirer.com/story/news/2022/05/23/je...
However I do not see anything resembling cell phone service happening until the 1970s.