What's the likelihood this leads to a change in government and the US embargo ending?
After seeing what happened in Belarus only a few months ago, quite low actually, at least in my opinion.
It's good to be dubious on day 1.
That said, I'm not sure Belarus is the best example for you to use re: it'll just burn out. Belarus is nearing the 1 year mark of the start of its protest cycle and is still very unstable and messy. It's unclear whether Lukashenko will ever have the degree of uncontested authority he had before this, even if it doesn't topple him.
Will this overthrow the Cuban government? I have no idea. This only started hours ago and no one has a serious idea how big or intense this is. That said, even if the answer is "no," No is not necessarily "the regime will just shrug this off." Some even failed revolts can have serious destabilizing effects.
