What you’ve mentioned doesn’t really narrow down much on why I am seeing such optimistic FTP predictions, training at a moderate to high volume and then getting decreases through successive blocks.
I think in my explanation it does 
When you first get the AI FTP Prediction it’s assuming you’ll do all thats laid out. If things change along the way (like the ones I mentioned) then it’s only natural the prediction will change… It also has more of a butterfly effect at the beginning than at the end of the 28 days.