Do flash sales come back?

Well, in previous years flash sales were simply daily deals repeats. Now they are more random.

Which probably means you won't see most of them, as last day sales were always about biggest names and biggest sellers, not small games.

But who knows what Valve will do.

No idea tbh, I hope some of them will be back for the encore, but let's wait for some expert's opinion.

There's never any consistency regarding the Encore sales. I'm not sure if its driven by the publishers asking for another shot based on results so far, or Valve asking the publishers. That's why its always a good idea to buy a game during a Flash sale, if you're going to purchase it at all.

it is back :D!! happy ending to me.