The requirements apply to all “Google-certified Android devices” which includes:

Devices with Google Play Store

Devices with Google Mobile Services (GMS)

Devices with Play Protect

All mainstream Android devices from manufacturers including Samsung, Xiaomi, Motorola, OnePlus, and Google Pixel

Custom ROMs without Google services & uncertified devices are not affected by these restrictions.

From the linked wiki.

There’s a legal process which may result in financial sanctions. Seems like there are 30 actice cases right now.

Here’s some general info, an FAQ and a database.