Originally Posted by
Xandrios
Likely low availability on that flight and the automatic rebooking mechanism keeping a few seats free. The PSL can likely override that, and as you have status, put you on that flight anyway. Which may be the exact reason why they don't automatically rebook that flight up to 100% straight away.
Even without any status at all, they would rebook you on that flight rather than having your overnight somewhere. The automatic algorithms are quite imperfect but the humans will always give you anything even remotely reasonable.