In a court filing submitted as part of its legal battle with the US Federal Trade Commission over its proposed Activision Blizzard aquisition, Microsoft has claimed Sony is "expected to release" both a PlayStation 5 Slim and a "handheld version of the PS5" before the end of this year.
Both machines were referenced during a paragraph (as spotted by IGN) intended to demonstrate that Nintendo's Switch should not - as the FTC is arguing - be considered in a separate market to Xbox and PlayStation based on price. It's a point Microsoft is determined to prove so it can more effectively assert its stated position as the underdog in the console market.
As part of its argument, Microsoft notes the Xbox Series S is $50 cheaper than Switch's OLED model in the US, with the $399.99 PS5 Digital Edition being just $50 more. It's here the company first makes reference to an unannounced Sony machine, claiming the latter is "expected to release a PlayStation 5 Slim later this year at the same reduced price point."