It's nonsense.
The circle shows a line basically right through the last known position within a range of acceptable error.
According to Imarsat, it must have remained in the same area and ran out of fuel in same area, as the last transponder signal.
What we have is an incredible error in assume the TIME of the last "ping" to be 7.5 hours AFTER the transponder stopped.
No, that last ping from my read occurred about the same time as the last transponder report.