Wouldn’t it be redundancy rather than termination? I don’t know about America but here redundancy tends to come with a nice pay out.
It depends an awful lot on the particular state.
Most of the US operates under at-will employment, which means the employee is under no obligation to work for the employer, and the employer has no obligation to keep the employee on - and can terminate them at any time, without cause. The lack of given cause doesn't mean that certain motivations, such as discrimination, are legal - which would be why an employee might sue under claims of evidence that those were the motivations.
Union laws are also per state and nationally set, and I'm a lot less clear on the separation between employee rights, union rights, and the powers of the National Labor Relations Board (NLRB, mentioned in the article). For instance, many states may say that union membership cannot be mandatory for employees - which both gives the employees more power to decide whether they think the union is properly representing their interests, and reduces the collective bargaining power of the union.
Not speaking to specifics of this particular case but rather proposing a hypothetical - one could see how matching union-negotiated salaries as well as adding on additional non-negotiated benefits like educational compensation might be used to attempt to severely weaken the union, especially in a trade with a high degree of turnover like retail. I do not know if Maryland has such union membership optionality rules, nor how the NLRB regulates such things.
There are laws about mass terminations as well - I seem to remember as an example that California has lower limits than the federal rules, requiring a certain number of notice if it is more than 50 employees or 1%. Since you usually aren't going to tell someone they are going to be fired and still let them come in, this effectively becomes a minimum amount of severance offered to workers in a layoff.
We have gained regulatory groups like OSHA to set standards/regulations for workplace safety and sanitary conditions, mandating breaks, and a federally set minimum wage. Unions seem to still seem to attempt to justify themselves in public opinion by saying they will fix unfair scheduling or discriminatory pay practices and the like, but generally these federal laws mean that union collective bargaining is usually being employed to negotiate better compensation rather than solving significant working condition issues.
That said, OSHA rules are still pretty broad, and an appropriate trade union may better represent and establish what are healthy working conditions for particular tasks/environments. I'm not sure the Maryland store, organized under the "International Association of Machinists and Aerospace Workers", truly is getting that benefit however.
