Just did a yahoo search...
Here is a link... The inital search looked like some mention of todays date... But maybe because of basketball playoff or whatever else... a decision was made to move it.
I am sure it is a taped event anyway... I'll check the site more..
It sounds like a decision was made to move it maybe even before the president's speech. ABC could have always delayed the start of it to broadcase it in full. I highly doubt that the Presidents speech will be lengthy.. It isn't a state of the union address.
In any case... I thought I saw, and now see it on the site as well that the 22nd is at least the current date.
http://abc.go.com/primetime/legendsball/