Disagree.
What other airline would have either bothered with such a blog post? None. It's rather clear there are other forces at play here.
You don't see any other reasons why the head of loyalty wrote a blog post, giving the negative reaction this particular devaluation received, particularly due to it happening with no advanced notice??? Perhaps they wanted to do damage control and highlight:
1. We are committed to keeping our program as a competitive advantage
2. We plan on giving notice for future devaluations
3. If you bought miles recently, we'll give you a refund