Not swapping a major component out, no.
But could Microsoft could theoretically have better yields than Sony allowing them to reduce their CU reservation? Sure. The reverse is also true. And in terms of memory, I would imagine that both manufacturers have built into their core design a degree of flexibility given how RAM prices fluctuate across RAM types. PS4 4Gb -> 8Gb was straight forward using GDDR5 clamshell setup but I wouldn't bank on such a large last-minute capacity upgrade with nextgen unless their current target is already low, like 12Gb.
Even with solid state storage, I hope they'll looking to let games have access to a minimum of 14Gb separate from the OS.
He's doubling down.