This commit seems to mostly be grammar fixes? If someone used a spell/grammar checker it might produce a diff similar to this. Why does the fact it was Claude and not Microsoft Word or other matter in this case?

Because Microsoft Word doesn't write blog posts for you

Edit: I just realized that Microsoft Word probably does do that now, and I hate it.

Copilot is the new clippy meme. Copilot is hiding in every MS product and is ready to write an email for you, anytime.

Yes but that commit doesn't support the fact that it has written it for the user.