diff --git a/.flowconfig b/.flowconfig
index 875fc6de97..0bd9289ffb 100644
--- a/.flowconfig
+++ b/.flowconfig
@@ -56,7 +56,6 @@ module.system.haste.name_reducers='^\(.*\)\.android$' -> '\1'
 module.system.haste.name_reducers='^\(.*\)\.native$' -> '\1'
 module.system.haste.paths.blacklist=.*/__tests__/.*
 module.system.haste.paths.blacklist=.*/__mocks__/.*
-module.system.haste.paths.blacklist=<PROJECT_ROOT>/Libraries/Animated/src/polyfills/.*
 module.system.haste.paths.whitelist=<PROJECT_ROOT>/Libraries/.*
 module.system.haste.paths.whitelist=<PROJECT_ROOT>/RNTester/.*
 module.system.haste.paths.whitelist=<PROJECT_ROOT>/IntegrationTests/.*
@@ -78,6 +77,7 @@ suppress_comment=\\(.\\|\n\\)*\\$FlowExpectedError
 
 [lints]
 all=warn
+unnecessary-optional-chain=off
 
 # There is an ESLint rule for this
 unclear-type=off
diff --git a/.github.flowconfig.android b/.github.flowconfig.android
index 94e6b74c94..83d6e22257 100644
--- a/.github.flowconfig.android
+++ b/.github.flowconfig.android
@@ -56,7 +56,6 @@ module.system.haste.name_reducers='^\(.*\)\.android$' -> '\1'
 module.system.haste.name_reducers='^\(.*\)\.native$' -> '\1'
 module.system.haste.paths.blacklist=.*/__tests__/.*
 module.system.haste.paths.blacklist=.*/__mocks__/.*
-module.system.haste.paths.blacklist=<PROJECT_ROOT>/Libraries/Animated/src/polyfills/.*
 module.system.haste.paths.whitelist=<PROJECT_ROOT>/Libraries/.*
 module.system.haste.paths.whitelist=<PROJECT_ROOT>/RNTester/.*
 module.system.haste.paths.whitelist=<PROJECT_ROOT>/IntegrationTests/.*
@@ -78,6 +77,7 @@ suppress_comment=\\(.\\|\n\\)*\\$FlowExpectedError
 
 [lints]
 all=warn
+unnecessary-optional-chain=off
 
 # There is an ESLint rule for this
 unclear-type=off
@@ -100,4 +100,4 @@ untyped-import
 untyped-type-import
 
 [version]
-^0.77.0
+^0.78.0
diff --git a/.gitignore b/.gitignore
index 50a3ed6420..4fb4a25d15 100644
--- a/.gitignore
+++ b/.gitignore
@@ -51,10 +51,6 @@ node_modules
 *.log
 .nvm
 /bots/node_modules/
-
-# TODO: Check in yarn.lock in open source. Right now we need to keep it out
-# from the GitHub repo as importing it might conflict with internal workspaces
-yarn.lock
 package-lock.json
 
 # OS X