It’s not difficult to understand. The SACEUR doesn’t speak for NATO as an organization and in fact the idea that Christopher Cavoli is “NATO’s top military officer” would come as quite a surprise to his boss Admiral Rob Bauer the Chair of the NATO Military Committee.
Admiral Bauer, unlike Cavoli, actually does speak for NATO.
What does Admiral Bauer have to say? His statements are the official ones, not the just opinion of an Officer.