I can confirm that First did change to Preferred Plus. I had to exchange the Fusion Titanium today since it was overdue for an oil change and its registration expires tomorrow and the reprinted contract shows me as "PREF PLUS/POINTS". Interestingly, the original contract on Sunday just showed Preferred rather than the First it has been printing up to last week.

It's still annoying that none of my earlier rentals this year count towards PC, but at least it's not a downgrade! (The 28K '14 Camry is more annoying than it being November instead of August before I hit PC)