HN has a big blind spot, in my opinion, around writing that isn't "purely technical". I've seen several cases of commenter complaining about "clickbait" for a blog post that I'd describe as "having a narrative hook and structure"
I'm specifically talking about the use case of "can we use natural-language tools to parse oracle text and produce functioning game objects in Arena". For that use case, it's completely sensible to look at the actual rules text and not reminder text.
Looking back further, there was confusion during preview season when people were looking at "fake/leaked" mockups that had incorrect text on them, but this also isn't a problem for the issue of "WotC themselves writing systems that can parse card text".
I don't think Prepared is ambiguous at all. It has its meaning defined in the CR (722) and every card that uses it has either a clear trigger condition or the "enters prepared" replacement effect. It's just a new designation and there are plenty of those already, including ones that are 10+ years old (Renowned, Monstrous, Level Up).
The Arena card engine is based on CLIPS [1] and not modern LLM-based tools. Magic cards are written in a very constrained language (usually called "card templating") that lends itself very well to machine-parseability.