CFET transistors are planned for somewhere between 2030 and 2040, and probably also require some tool improvements and/or new tools.
So I think I would somewhat disagree on this because there are already some existing tools that have been developed for MRAM manufacturing : it is likely that, at least some, of those tools could be re-used and improved for spin related technologies.
That is the reason why I believe that as a 1st step, MRAM should first be scale-up to high HVM for depreciating those tools and make them more common, and generate revenue to further invest in R&D to improve those tools. Then a few years later, it would lower the cost to migrate to other spintronic related technologies.
Let assume it would cost (ex: 100) to develop CFET, then I would agree that it will be more expensive to develop spintronic related technologies (ex: 120 / 150) but overall, the benefits will also be much, much higher (much better power efficiency, NVM, start the transition to spintronic a decade earlier,…)
That is where incentives and the US CHIPS Act could play an important role by helping fund the cost gap between CFET / spintronic to accelerate the transition to spintronic related technologies.
For example, it could have granted funds to scale-up a HVM fab for 32Gbits+ NVM MRAM in a way that makes MRAM reasonably competitive with other entrenched volatile DRAM.
It is the same principle than the transition from ICE vehicules to EV, or from fossil fuel to solar photovoltaics energy : there is a need of some incentives at first, to help the technology become cost competitive.
Alternatively, without incentives, it will likely take much longer (ex: OLED versus LCD).