As far as I can tell, the ICP is upgradable, through software upgrades,
but don't worry , it's really good ,LM says so themselves !
Quote from a LM whitepaper
We are simply upgrading the computers in order to run the next block of software.
Here’s an example we can all relate to: you buy a new laptop and you know the moment you buy it’ll be obsolete in six months. There’ll be something better by then. So what if the seller said, “In order to preserve your edge let’s plan on installing a better processor six months from now. We’ll make it as good as the one we’re going to sell in six months.” You would say, “Yea, that makes sense” because otherwise, as a consumer, you’d keep waiting in anticipation of a better laptop in six months.
That is exactly what the F-35 program did.
That sounds worryingly a lot like 'the ICP is so vital to the whole EWF package that it will be virtually impossible to use a whole new design once it becomes too obsolete to upgrade solely by giving it a software upgrade.