This is very similar to "a11y"[0] and "i18n"[1]. The abbreviation of words using this technique has become surprisingly common in the software industry.
I'd say the vision impaired are going to understand what "ay-one-one-why" means about as fast as the rest of us. I'm not a fan of the cutesy letter-number jargon either, if you're typing about it in Slack, sure, okay, but it shouldn't escape confinement.
But it's equal-opportunity annoying I reckon: no one knows what the hell `a11y` is about when they first see/hear it, but not in a way that's more onerous for screen reader and braille users than for anyone else.
Sure, that's reasonable. Kind of circles back to "a11y" being technical language, which refers to a term of art, "accessibility", which is not identical to the word "accessibility" itself. This is at least part of why it gets used, although the main reason is really that a11y is easy to write and fast to read, while accessibility is neither.
[0]: https://www.wordnik.com/words/a11y [1]: https://www.wordnik.com/words/i18n