The government doesn't guarantee you a platform for your speech. In the US, you have the right to free speech in general, but there are specific carveouts.
For example, I can say here on HN "fuckity shitting fuck shit" and not be fined or imprisoned. But try saying it to a judge during a trial, and the outcome will likely be different.
And it's the same for saying it on broadcast television at certain times of day and in certain contexts.
Without more details, that doesn't explain why the FCC might not apply such arguments to Alexa (or the news, or indeed anything). All speech occurs at some time and place, and in some manner.
Most of us here will be surprised by things in Law School 101 (I know I have been, but only because it being phrased like this came up one time in a Legal Eagle), and many (like me) aren't American and don't get the meme-sphere of assumed knowledge about the FCC or whatever, so a broader ELI-15 might be helpful.
As far as I know, the FCC regulates content broadcast over the airwaves under the premise that the EM broadcast spectrum is a limited and public resource. That argument wouldn't apply to software or content on the internet.
The FCC can't regulate the sites spreading misinformation, why would it be able to regulate the AIs that consume it?
Laws can change, and this is a mass produced consumer device with a single AI behind it (and for most people there's only Alexa, Google, Siri, and ChatGPT, with e.g. Cortana being in the "I didn't know they even did that" category) making it an easy target.
