It only has probability 0 or 1/n, where n is the number of compatible next words.
There are no numbers in https://github.com/adamjgrant/Tiny-Predictive-Text/blob/main...
A Markov chain could express probabilities like completing "the original" to -> "poster" (0.1), -> "McCoy" (0.2), -> "and best" (0.7) which I don't think this does. But I am tired and maybe also misunderstanding.