Autocorrect unleashed doesn't sound like any AI either but that doesn't stop anyone from calling it that
The simplest way to build autocorrect is to have a dictionary, look it up for each word, and suggest the "closest" dictionary word if a typed word is absent from the dictionary.
It has existed way before transformers and on platforms that couldn't dream of running even the smallest transformer.
I think you'll find the broader idea of word vectorization to be remarkably similar to what text transformers do.
We're just talking past each other. I agree that a tree is the historical solution. I didn't catch that part.