Maybe we just had a misunderstanding. What I was trying to say: Once this happens and everything breaks they will have an incentive to fix things quickly.
By no means do I expect vendors of "SSL inspection" devices to act any sooner than that.
They will just add an additional TLS proxy with a self-signed cert that ignores all validation. Security will be broken but users will be able to continue to do their work.
is looking at a corporate firewall blocking Stack Overflow right now
... "practical" is setting your expectations a bit high.