I would be surprised if it would allow any meaningful reduction in cooler size,
a bare die from TSMC is ~$85-95 for the ps5 SOC, say 5 nm is roughly twice the price of 7 nm at TSMC if the link below is anything to go by, lets be generous and say a 6 nm chip is only 20% more than a 7nm one, so that would be $102-114 per PS5 SOC, even if the 6nm soc produced a third of the heat of the 7nm version there is no way you could make a saving of $15-19 in the cooler that they have.
The only way I can see it making sense is for a PS5 slim, just so it can have a smaller footprint, allowing smaller boxes/cheaper shipping and all the rest of it. The problem there though is that unless they start selling a PS5 slim in the next 6 months it doesn't matter, because once ps5s are being shipped via container ship the marginal savings on shipping will be immaterial.
The only reason it makes sense is for capacity.
It is interesting that microsoft seems to have more SOCs coming off the line, they have less retail units out there than sony it seems, iirc phil said that they started producing systems 2-3 months ago, and anecdotally a bunch of people were comparing series x build dates on resetera, the earliest build date anyone found was mid july.
I wonder how many Xcloud server blades they are building? surely it must be in the millions if they are dual use for AI stuff in the data centre. bdsams, the guy who leaked the Series S, said the first xcloud server blades rolled off the line second week of september.
I really want a blow by blow behind the scenes book about this launch one day, from microsofts and sonys perspective, Im not holding my breath though
https://www.techpowerup.com/272267/alleged-prices-of-tsmc-silicon-wafers-appear