No, they are not.
People have been brainwashed and legal systems have been paid and bought for to consider them as such, just like corporations have been whitewashed to be treated as "persons".
In any case, we regulate all other kinds of speech as well: explicit content, libel, classified information, cigarette ads, and so on.
I don’t think you need to count companies being able to put any message out there as free speech.
Granted, that's proven to be a horrible concept. So let's repeal that.