This has something to it. A TL where labor organizations concentrate on providing financial and other beneficial aid to workers, rather than political agitation and a push for public welfare, is likely to be a lot more libertarian. Credit Unions, building societies, mutual aid societies providing health and unemployment insurance, etc etc.
Perhaps a Great Depression that isn't so devastating. This would also provide a constituency for a second coming of the Thomsonian movement. Medical licensing (at least this wave) is only a generation old by the 1920's, and the last time it was overthrown is just out of living memory.
I would add that some of the radical labor organizers who were imprisoned during the Red Scare began to focus on political organizing instead of labor organizing, solidarity, and mutual aid. From their perspective, syndicalism's disdain for political organizing could seem mistaken.
I imagine that if the wars and revolutions in Europe had gone differently enough, Wilson might not have taken the chance to intervene, and the Red Scare might not have been as drastic as in our time line. And maybe those radical labor organizers who turned to political organizing would have the chance to ally with Social-Revolutionaries, or Marxist-Luxemburgists, or anyone but Marxist-Leninists.
You'd still have some authoritarians, like the Francis Bellamy types, but you'd have more libertarians than authoritarians on the left.
I don't know how all that would affect the rest of the political spectrum, but I imagine it would tend to benefit the mutual aid societies, fraternal societies, and mutual aid actions for dealing with the Depression.