No it wasn't, let's not start spreading misinformation.
Spellcheck was around since the 1990s. Originally it was simple heuristic-based against a dictionary (localized, maybe also allowing some personalization). Noone called it AI, pre-2010 AFAIK. Can you show any pre-2010 citations for any actual mainstream consumer-available spellchecking using AI?)
I only see a small number of references to the use of AI in spellchecking, mostly post-2018, and they're still the minority of mentions of spellchecking, dictionary heuristics is still a simpler much more basic technique, even if ads don't say that. (There are now (post-2018, GPT-era) AI-based spellchecking/writing-coach/style-type startups, and obviously there are also many companies trying to infuse their collateral with claims about AI, or pivot/bolt on AI to a non-AI concept. Let's not muddle all that together.)