Well at least sometimes it is correct. If anyone can use them, there are 2 F seats on 5/11 on the 388 FRA-SFO. Shows on UA, AC, and NH

Edit:
As of 10:30am PDT on 5/10, these seats are gone from NH, UA, and AC, so the statement of "not a real time link" is absolutely wrong. The sites are getting real data quite quickly, or at least every 12 hours. I've seen false availability show up on UA.com for days and even weeks