How will unions navigate contract negotiations if the government implements Medicare For All?

Hello all,

Union lawyer here. I'd like to preface that our union limits the lawyers from getting too involved in contract negotiations, because they want to empower the members to fight for themseleves. So, I am not the most experienced in this realm, and the hypothetical I'm proposing might already be "solved".

However, I've been pondering a question and I thought I'd crowdsource some thoughts and opinions. Supposing this country somehow gets better and we magically get Medicare For All, how will unions navigate this and negotiatie future contracts?

It's rather obvious to me that one of the key benefits of union membership (and employment in general) is health insurance. In a world where we no longer have to contend with the most of the bullshit surrounding insurance companies, what should unions do? How do we prove our worth to the rank-and-file? How will this change contract negotiations? Will unions have to fight harder in other subject areas, since one of the main benefits is now garunteed by the government?

I know this is a very loose question, but I'd love to hear some discussion on it.