Whether or not a replacement exists is orthogonal to whether the code in question is Free or not, right?
The presented argument is a false dilemma. The short-term options are indeed blob or brick, but the long term options are blob, brick or freedom. Clever use of your freedom (and power) of choice will bring us all freedom, because hardware suppliers ultimately want to sell their stuff. Unwise choices will lead to progressive erosion of freedom, with more blobs controlling more parts of our computers.
As to whether non-Free code on flash memory is ok, I wonder where you got that idea from the announcement. If it's there at all, it was my mistake, and I'd very much like to correct it.