Those union members are perfectly free to create was is called a members only union, which only represents its own members who voluntarily join the organization.
Doing that avoids any of those conditions that you are talking about.
Then you don't understand what "bargaining rights" are. It is absolutely fully legal for a members union to negotiation on behalf of its members, if those members consent to it.
In the same what that it is fully legal for me to hire a lawyer friend of mine, to bargain on my behalf.
What it can't do, is force everyone else, who is not in the members only union, to go along with that bargained contract.
So please, do not say that their bargaining rights are taken away. Instead be honest and say that their ability to force everyone else to have their bargaining rights taken away, and given to the union, against the wishes of those employees, is being removed from them.
Well, I am talking to you here though right? And there is context here, to this subthread that you are ignoring/missing.
If you want to say "Non union members cannot force 3rd parties to work with them, if they don't want to" Then yes I agree.
But the context of this subthread was about the idea of who is or is not forcing people to do things.
So, to get back to the point of all of this, I was initially responding to someone else who tried to claim "That's not exactly liberty".
But it is liberty. Liberty is the idea of consenting parties, not being forced to do things. So yes it is liberty to say that people can join non-members unions, but that those non-members unions cannot force other people to do certain things.
Do you understand the point and context of this all? It was about whether that is "liberty" or not, which just means who is or is not forcing others to be in the group, or forcing people to work with your group.
Unless you're suggesting someone in this position should have to retrain for a different industry. Which, sure, ok, I guess, but the cost to do so might be quite high to the point of being life-ruining.
And then workers who prefer the union, can join members only unions that are not forced to represent people not in them.
The right are proponents of right-to-work legislation that force unions to represent non-dues paying members for free, and nullifies their private contracts. That's not exactly liberty, and it minimizes risk for owners.