Niantic has announced that they will be running 2 live tests through December 2020, one for Raid Battle rewards and another for Egg management.

Raid Battle–reward and Egg-management tests happening soon

Trainers, We will soon be conducting some tests regarding Raid Battle rewards and Egg management. The details of the tests are as follows.

• Raid Battle rewards will be adjusted in the United Kingdom and Ireland. These adjustments will be temporary and will begin on Wednesday, December 9, 2020, at 1:00 p.m. PST (GMT –8) and end in early January.
• Egg-management tests will take place with some Trainers globally in two variations. In both variations, Trainers will be able to store up to three additional Eggs from weekly Adventure Sync rewards and Team GO Rocket Leader battles if they already have nine Eggs in their Egg storage. In the first variation, all 12 Eggs will appear in the same section in the Egg-storage tab. In the second variation, the additional Eggs will appear in the “Bonus Storage” section in the Egg storage tab. Trainers involved in either of the test variations will also notice that newly acquired Eggs will not count toward their Pokémon storage limit until the Eggs are placed in Incubators. Both variations of this test will begin on Friday, December 11, 2020, at 10:00 a.m. PST (GMT –8) and will continue for an indefinite amount of time. Based on the results, more Trainers will be brought into the tests over time.

Please be aware of your surroundings and follow guidelines from local health authorities when playing Pokémon GO. Upcoming events are subject to change.

Source: https://pokemongolive.com/post/raidbattle-egg-tests-2020/?hl=en