Hi Brad,
At the very least we I think should reduce the bits to 25GBASE-xR and 25GBASE-xR-S ability bits. We only advertise those two during AN, so no need to have independent bits for backplane and cables in EEE as well. I could see setting only the -S bit happening when a PHY supports deep sleep for 10G speed up, but not RS-FEC operation.
Which then begs whether it should be 3 capability bits based on operating mode of the 25G PHY: 25G 64b/66b deep sleep, 25G BASE-R FEC deep sleep, 25G RS-FEC deep sleep.
-Jeff