Coming in late but since I'm an author who has two projects in pre-production, I can share how this affected my recent contract.
The first offer stipulated that I'd be paid roughly 20% of a reasonable buy price and the rest would come from residuals if/when the show went into syndication.
My film agent immediately rejected it because streaming shows don't go into the old network syndication model, so they were offering me 80% of nothing.
The contract I ended up signing had a fair price that would be paid on the first day of principle photography, then a set payment per episode produced. No residuals.
It's been my understanding that SAG actors were offered similar pay structures, where most of their earnings would come from some vague, ill-defined source, if at all.