The company management is an interested party in any labor dispute and has a right to a voice in any union organizing effort. It is called free speech. Both the union organizers and the company have a fundamental right to it. You are advocating a limitation on the free speech of one, but not the other, party.
You have not addressed the highly counterintuitive implied proposition that signing a card shoved in your face by a union organizer is a more reliable way of determining the real intentions of the workers that are the target of the organizing effort than an anonymous secret ballot. They are being asked to surrender 1-2% of their pay to be forcibly collected by a third party, and also have a right to consider both perspectives and express their choices outside the view and snooping of those who would influence their choice.
I suspect if corporations proposed that such unionizing efforts be decided by employees filling out a form in the HR office of the company you would find that highly intimidating and unfair. You are merely rationalizing intimidation by labor union organizers as beneficial because it empowers a political force that you consider desirable and achieves a result you want. The cost of that, of course, is the freedom and free choice of the employees themselves.
You also imply that during current organizing efforts companies practice intimidation, but unions don't. And assert you have evidence of this, but that it is all exclisively from union sources that you assert I will wrongfully discount. You also ignore the extensive public record of union corruption, criminal activities and collusion with organized crime
Perhaps you see yourself as a member of the new "vanguard of the working class", one who knows better than they do what is really good for them. Think about it. It's all been tried before and the results weren't good.
In any event the argument is academic, because the proposed law isn't going to be passed.