No. I have been tracking the difference between announced engagements and what actually happens (I know, I am sad).
It has never been published anywhere. Williams attendance is on the Royal website and was only put on there on either 15/16th. That is when Catherine's engagement on 18th was also posted.
its over enthusiastic "fans" assuming that she would be there and posting on their blogs.
They created their own disappointment!
The anti-fans are claiming it was on the KP website until she cancelled.
On KP's twitter for March 11th, it does mention the engagement for the 17th.
So the plot thickens...
Could she have been scheduled?
Could KP twitter manager have typed both Duke & Duchess without confirming or just out assumed both would attend as they had previously and then was told only William would attend so Duchess was removed but not before some of her 'critics/fans saw the tweet?
There is a 14 minute gap between Battalion tweet 3:45 and the Commonwealth Tweet 3:31. The Harry tweet is also for 3:45.
It look like fat fingers might have caused the problem or an overzealous staff member.