Whether he was conscious of the change or not (and I think he was, but that’s another minor detail), Matt’s warning has set off what I would describe as an existential crisis in the WordPress community — even though I don’t think we’ve fully understood what it means, and the impact it will have.
And what will the impact be for the teams navigating this change? Some organisations opt to keep their existing engineering teams and augment them with a React-focussed team; others embed the React engineers throughout the engineering organisation. Both approaches are valid, and they both have downsides. The “React skunkworks” allows you to move faster, but at the risk of isolating knowledge. Spreading the talent is good for ‘lifting all boats’, but propagates change much more slowly; and your expensive React engineers end up focussing most of their time on teaching and mentoring instead of really engineering. Unless they genuinely love the educational process, it quickly turns into “just give me an API and I’ll handle the React bits”; that’s no way to build strong knowledge across your teams.
(And all of that barely dives into the impact this will have on the WordPress ecosystem: the realignment of power among third party plugin and theme developers, the emergence of new community superstars, the shift in WordCamp programming, etc. The crisis grows.)
So the best advice I can give is: work quickly to re-evaluate how you’re screening talent. Allocate time for your existing teams to retrain. Open the lines of communication with your engineering managers to determine how to start integrating Gutenberg workflows into your teams.
You have no choice.