When Joe Biden and Congress enacted legislation in December that blocked a threatened freight rail strike, many workers angrily faulted Biden for not ensuring that the legislation also guaranteed paid sick days. But since then, union officials says, members of the Biden administration, including the transportation secretary, Pete Buttigieg, and labor secretary, Marty Walsh, who stepped down on 11 March, lobbied the railroads, telling them it was wrong not to grant paid sick days.

“We’ve made a lot of progress,” said Greg Regan, president of the Transportation Trades Department of the AFL-CIO, the main US labor federation. “This is being done the right way. Each railroad is negotiating with each of its individual unions on this.”

https://www.theguardian.com/business/2023/may/01/railroad-workers-union-win-sick-leave

Yes, but he shouldn't have shut down the negotiations in the first place.

1. It's bad optics for him. He would have known perfectly well which action would be covered by the media, and which one wouldn't be, and how that would look. It ends up looking like a strategic choice to appear anti-union.
2. It weakens the railworkers union! Now they know they can't get their demands on their own, they literally have to have federal intervention. Their bosses also know this. Biden also knew this.