Minecraft wiki entry for Nether_Update, associated text: 1.16.1 was released to fix stability issues with Realms.
1.16.2 added piglin brutes and experimental support for custom biomes.
1.16.3 was released to fix a critical duplication exploit.
1.16.4 added social interactions screen feature.
1.16.5 was released to fix two issues related to server crashes.