Then, by "freedom and security" you mean immunity to hackerdom, and not to
instutional intelligence (Intel and various intelligence services they
possibly cooperate with).
Because, with a proprietary µcode and architecture, all those CPU's were
already compromised when they are first sold. Meltdown and spectre opens your
system to hackers, but it was already open to Intel for years. And the µcode
update libreboot might provide or not will not protect you against Intel (and
their accomplices) but only against the hackers.
So the question is rather simple, really. Which is;
"Shall I continue to be open to just Intel et.al. (with µcode update), or
shall I be open to *both* Intel and hackers (without µcode update)?"