What do you want people to do? I don't think there is any realistic thing you can do but wait. I rather have a good game than a rushed bad game.
I expect them to create an achievable, measurable project plan and stick to it. I do it at my job all the time and have deadlines to meet on development, it isn't all that hard to do, especially when you don't have big clients demanding you bring the dates forward. They set expectations, then let scope creep and marketing get the best of them. Customers should not just accept that, especially since we already gave them our money. Already paid customers are being forced to wait for content in order to provide a more expensive and appetizing package to new customers.
And Shovel Knight King of Cards is hardly going to be a "bad" game regardless. This mentality is exactly what I was talking about. That old stupid quote from Miyamoto has warped people's brains. Just because a game is delayed, doesn't mean it will be good (ahem, Mighty No. 9), and just because they push to meet a schedule does not mean it will be bad and extra time does not equate to improvement. What Miyamoto meant that is literally lost in translation is that additional time can improve a game, not that people should consider it a guarantee. He was giving solace to people waiting for OoT and people have gone on to equate the quality of that game to all delayed games.
Showdown should never have been combined with King of Cards. Their dev team couldn't handle it within a reasonable timeframe that they defined. Keep in mind the original date estimate of the Amiibo and King of Cards was late 2017 to early 2018 and that was before the "not so set in stone" April date.