ESRB to stop offering free ratings for digital-only games
For games that launch as digital-only in countries that use the ESRB ratings board, a free rating is given to them via their Short Forms process. However, once June rolls around, the ESRB plans to cease offering this. This will mostly affect independent developers that have games that are made on a low budget, as registering for an ESRB rating can cost $1000-3000 for them. There is a way to circumvent this, though, as digital games can still get a free International Age Ratings Coalition (IARC) rating, which is accepted on the Nintendo eShop, Microsoft Store, and Google Play Store. IARC ratings notably leave out the PlayStation Store, which still require games have an ESRB rating to be allowed to be sold on PlayStation systems.
Source
ESRB ToS