In case of Ghomeshi the desirable outcome is to dismiss or mock him, not to attempt to take his voice away. Whatever benefits of deplatforming Ghomeshi are, the can't possibly outweigh grievous harm of enabling and propagating censorship.
So what is your proposed legislative remedy to mandate the exercise of speech in the free market? I would describe this as limiting the speech of the publication. This is what you're asking for, ultimately, which I find far more Orwellian than allowing the market to decide what speech is profitable to promote. For example, why is Ghomeshi's speech entitled to appear in NYRB or any other publication? If his essay was pure dogshit (I know, it's a stretch of imagination), a fantasy of melancholy devoid of any factual statements, why should anyone be mandated to publish it? What's the market circulation requirement, how many publications does it have to appear in to satisfy?
Perhaps you think this goes too far - then is the remedy to limit the speech of his private citizen dissenters? Rate limit their tweets?
I honestly can't think of any solution that would satisfy your objections here, unless objection itself is the end goal, in which case why should your objection mandate any action at all? In the example of reinstatement of the editor, even this tramples on the rights of the publisher to exercise their own speech. I'm not trying to be glib here but I'm left with the conclusion that you're objecting to freedom.
More so, with most of the speech moving to digital format you have an issue with corporations like Google, Twitter, and Facebook having the power to effectively silence you. In turn, these corporations can be pressured into censorship.
What is the point of having theoretical free speech rights if it can't be exercised unless you are independently wealthy and powerful?
In a sense, I agree with you here. The danger with those platforms is proportional to their approach to monopoly, and the intersection of the first amendment is along that approach. I think monopoly is the true evil in this case, though, and fortunately (as you demonstrate) they are not quite there yet. I also agree that inequality of wealth is a significant evil behind asymmetric exercise of speech, but especially in regards to political speech.Common Sense
is an excellent and relevant study of the forces of the market as it applies to speech. At first he had trouble finding any outlet for his views, but eventually he found a publisher willing to take the risk (I assume politically as well as monetarily). Once published though, it found so much political (and market) traction he ended up having to battle the initial publisher over attempting to publish a second edition against his wishes. Thanks to the technology we are currently using, if this were to happen today, his barrier to initial distribution would have been far lower.