"Also, be aware also that some serious contingency planning might be needed if Europe’s Data Protection Commissioners judge that the Privacy Shield does not provide an adequate level of protection."
Not contingency planning, just planning.
Schrems should have been a wakeup call. Until the US totally changes its prying ways and overall approach to personal data no fig leaf arrangement is going to get past the ECJ again. I suppose the US industry could buy itself a better government but it will be a lot cheaper and quicker to shift processing of data to non-US data centres protected from the US govt by an adequate legal firebreak.
This is not an issue that's going to go away.
And the UK govt. should consider the effect of continuing along its merry way in the event of a Brexit. It's going to make doing business with the EU a whole lot more difficult because they'll have put us in the same sin-bin as the US.