54 active CU out of 60 makes the most sense to me.
The PS4 Pro was 2x CU (18CU on PS4 & 36CU on PS4 Pro) with a butterfly design that shut down half of the GPU + downclocks for its base compatibility mode.
For the PS5 Pro it could just be a 1.5x CU approach instead (36CU on PS5 & 54CU on PS5 Pro) with a design that shuts down one third of the GPU + downclocks for a base compatibility mode. Wonder if this is the case as it would make sense with the supposed "Trinity" codename/moniker we heard earlier on.
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As for the whole Xbox launching a new console generation a year or two early; I don't think the next gen really starts until Sony says so unless MS can pull a rabbit out of the hat with their acquisitions and drop some major exclusives with it.
Not to mention, if MS drop an Xbox in 2025-2027, then Sony would come by in 2028 an entire generation or two of Zen & RDNA ahead (possibly with some select bells & whistles from the gen after that too), along with a smaller node process. Then MS will be behind again. Power may not mean everything, but Sony having a major performance lead across the board on a smaller process, likely with additional featuresets, would be significant.
I think MS' would be hamstringing themselves for very little gain. I think 2027 Xbox "5" & 2028 PS6 is about the most I'd expect (I'm adamant this'll be an 8yr gen, at least for Sony). MS just need to turn up and do a better job, I think they'd just be complicating things by trying to go for 2025/2026.