If the EUA has been modified to not use the F bucket but rather a hidden bucket, then it makes sense that they would allow the F bucket to get filled up. That means mileage upgrade, positive confirmation upgrade, full fare Y customers etc., can get the seats whenever they want. The "freebie" crowd will need to wait for the EUA to get upgrades.

What CO needs to confirm is whether the elite complimentary upgrades still come out of F and if there is a F seat available in the 5-day plat window, will a plat automatically get it?

One way to check is to see if the F inventory starts to change consistently in the elite upgrade windows. If F continues to have seats till the last day, then the elites are not being upgraded as before (with the assumption that there are always more elites than upgrade seats available).

As someone pointed out earlier, all that matters in the end is whether you consistently get upgrades that you expected.