Smart move by Sony. Even if the Switch is sold out now - i suppose there's many people out there who were waiting for Nintendo's latest offering to the console landscape to make their purchase decision.
Sure, the Switch is more or less hard to get right now, but Sony's willing to give up margins for a further boost in market penetration - with stronger and stronger ecosystem lock-in due to paid subscription models and digital purchase of games, market share is more valuable than ever before, even in the long run.
It's actually really smart timing. All the player's cards are on the table - yet the Scorpio is too far in the future.
It's the same reason Microsoft unveiled their "Netflix for Games" thing, and didn't save it for E3.