Android already allows sideloading.

Epic's lawsuit against Google is about the Play Store being an all or nothing affair. If you want in the play store you use their IAPs, or you do what Epic has done and make your users sideload and deal with the extra tech support and discoverability challenges that presents. Epic want to be in the store but not use Google's IAPs.

This is a bit different from the listed act and the complaint against Apple where you're just now allowed on iDevices without complying