Not to mention there are no "alternatives" that you can look into to purchase these replacements. You are essentially just locked to purchasing from Framework only
Are there any reports out there of macbook OTA updates causing laptops to become entirely unbootable with no recovery options (and, in case it actually happened, Apple refusing to fix/replace affected laptops at no extra cost)?
I am yet to hear of it being a thing, and I would love to be proven wrong.
Having said that, MacBook is a very homogenous machine with minimal choices (which can be a good thing) so testing upgrades patches on them should be fairly easy as compared to other vendors (a good outcome of that thing).
With framework and effectively with other vendors, this is where a lot of problems come from. And the problem is significantly harder.
As far as I am aware a failed bios/firmware update on any device can cause it to brick, thats why they always come with massive warnings everywhere. I personally do not just do bios updates because some OEM marketing said so. The old saying does me well, "If it aint broke dont fix it"
Various enterprise boards with BMCs can flash the BIOS from the BMC even if the BIOS is fucked.
You might even be able to do that with Intel AMT, but I've never had occasion to try.