"Sounds like a good start date for this year. I'm sure you've read Krudmeister's TJ from 2009."
I believe that he is starting way too early for a record attempt, (good start time for yo yo.) It is interesting that he is choosing both the record and a yo-yo as a goal. I would think that would be almost mutually exclusive. Why? For a record attempt you would select a start date that would maximize the trail conditions for the full length of the hike. For a yo-yo you would want the earliest start that gets you to Canada the earliest, not nessesarily the fastest, so you turn around and fly back to and through the Sierra before the snow starts in he fall.
His start date of May 20-25 is the exact same time that I started last year which I believe is perfect for a high speed yo-yo but too early for a record attempt, especially one that is targetting under 60 days. So at that pace he would hit the following points/dates:
Kennedy Meadows - June 7th
Sierra City - June 27th
Ca/Or Border - June 30th
Cascade Locks - July 10th
Canada - July 21st
I don't think that the trail will be impassible by any stretch but there will still be significant snow to slow him down especially in Or/WA. When Scott and Adam set the NoBo record in 2009 they started June 8th which gave them an additional two weeks of meltout. They hit KM on June 26th allowing them to fly through the Sierra and beyond. (Many people get so focused on the Sierra and snow they ignore the fact that a fast hike will also hit snow up north. I found that out last year when snow slowed me down in OR and WA in August.)
One thing that I noticed last year on Sam Fox's attempt... if you want to duplicate or surpass Scott's feats on the PCT it would be wise to follow his timeline. Nobody knows speed hiking the PCT like Scott.