I'm sure the protests and bad press in general were also a catalyst for the quick turnaround. The Avenger's cast was vocal about the bullshit and Marvel's their cash cow so they had a lot to lose by kneeling before Trump permanently.
On a positive note, this should have sent a strong message to every big corporation. The American people and the rest of the world are getting fed up with this fascist regime and they're not afraid to take action. Corps need to choose the side that will generate the most revenue since that's all they're in it for.