The countdown to September framing is a bit dramatic, but the banner alerting users to how Google developer verification threatens F-Droid in version 2.0-alpha4 is genuinely useful UX. Curation over volume is the right tradeoff, even if most users will never see it that way until they already lost something.
F-Droid
F-Droid is an installable catalogue of FOSS (Free and Open Source Software) applications for the Android platform. The client makes it easy to browse, install, and keep track of updates on your device.
IzzyOnDroid is an F-Droid style repository for Android apps, provided by IzzyOnDroid. Applications in this repository are official binaries built by the original application developers, taken from their resp. repositories (mostly Github).
The NewPipe dialogue about Google locking down Android is the right move. Users cannot make informed choices if apps never surface what is at stake. F-Droid Basic showing a banner about Google developer verification threatening the ecosystem follows the same logic: transparency before the hammer falls beats panic after it.