I'm getting the same thing. I uninstalled everything and then repeated the steps again with the Console application open and saw this during the "C-R" in the software update pane of system settings: 2020-11-10 18:06:07-08 theon softwareupdated[375]: bridgeOS: Minimum bridge version requirement satisfied ((null)), skipping search for bridgeOS update 2020-11-10 18:06:13-08 theon softwareupdated[375]: bridgeOS: Minimum bridge version requirement satisfied ((null)), skipping search for bridgeOS update 2020-11-10 18:06:25-08 theon softwareupdated[375]: bridgeOS: Minimum bridge version requirement satisfied ((null)), skipping search for bridgeOS update 2020-11-10 18:06:49-08 theon softwareupdated[375]: JS: No bundle at/Applications/SafeView.app 2020-11-10 18:06:54-08 theon softwareupdated[375]: JS: No bundle at/Applications/SafeView.app 2020-11-10 18:07:05-08 theon softwareupdated[375]: bridgeOS: Minimum bridge version requirement satisfied ((null)), skipping search for bridgeOS update A bit more context after trying the installation again after the above messages: 2020-11-10 18:11:50-08 theon osinstallersetupd[2411]: Retrieved package com.apple.dmg.BaseSystem (linkfile-validated:///System/Volumes/Data/macOS%20Install%20Data/UpdateBundle/AssetData/Restore/BaseSystem.chunklist:::/System/Volumes/Data/macOS%20Install%20Data/UpdateBundle/AssetData/Restore/BaseSystem.dmg) 2020-11-10 18:11:50-08 theon osinstallersetupd[2411]: Started downloading package com.apple.pkg.BridgeOSUpdateCustomer (http://swcdn.apple.com/content/downloads/41/51/001-73002-A_WRHOPHHLA3/wt9h9ieu492d5iadokij8dvq8t2dzg5sgg/BridgeOSUpdateCustomer.pkg) 2020-11-10 18:12:12-08 theon osinstallersetupd[2411]: Retrieved package com.apple.pkg.BridgeOSUpdateCustomer (http://swcdn.apple.com/content/downloads/41/51/001-73002-A_WRHOPHHLA3/wt9h9ieu492d5iadokij8dvq8t2dzg5sgg/BridgeOSUpdateCustomer.pkg) 2020-11-10 18:12:12-08 theon osinstallersetupd[2411]: Started downloading package com.apple.pkg.BridgeOSBrain (http://swcdn.apple.com/content/downloads/41/51/001-73002-A_WRHOPHHLA3/wt9h9ieu492d5iadokij8dvq8t2dzg5sgg/BridgeOSBrain.pkg) 2020-11-10 18:12:12-08 theon osinstallersetupd[2411]: Retrieved package com.apple.pkg.BridgeOSBrain (http://swcdn.apple.com/content/downloads/41/51/001-73002-A_WRHOPHHLA3/wt9h9ieu492d5iadokij8dvq8t2dzg5sgg/BridgeOSBrain.pkg) 2020-11-10 18:12:12-08 theon osinstallersetupd[2411]: Starting bridgeOS update prepare 2020-11-10 18:12:13-08 theon osinstallersetupd[2411]: bridgeOS prepare summary: 17P6610 -> 17P6610, update = 17.16.16610.0.0, brain = 17.16.16610.0.0, variant = com.apple.bridgeOSCustomer, macOS = 19H15 (customer), project = BridgeOSInstall-80, userAuth = 0, prod fused = 1, model = j152fap, client = InstallAssistant, retries = 0, session = C812ABD5-3E91-4C26-A207-1D1493050647: Error Domain=BOSErrorDomain Code=110 "The bridgeOS update doesn't satisfy the given minimum version requirement." UserInfo={bridgeVersion=17.16.16610.0.0,0, minimumVersion=18.16.12561.0.0,0, catalogURL=https://swscan.apple.com/content/catalogs/others/index-11-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog, NSLocalizedDescription=The bridgeOS update doesn't satisfy the given minimum version requirement.} 2020-11-10 18:12:13-08 theon osinstallersetupd[2411]: bridgeOS update prepare complete 2020-11-10 18:12:13-08 theon osinstallersetupd[2411]: bridgeOS update prepare failed: Error Domain=BOSErrorDomain Code=110 "The bridgeOS update doesn't satisfy the given minimum version requirement." UserInfo={bridgeVersion=17.16.16610.0.0,0, minimumVersion=18.16.12561.0.0,0, catalogURL=https://swscan.apple.com/content/catalogs/others/index-11-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog, NSLocalizedDescription=The bridgeOS update doesn't satisfy the given minimum version requirement.} 2020-11-10 18:12:13-08 theon osinstallersetupd[2411]: Operation queue failed with error: Error Domain=com.apple.OSInstallerSetup.error Code=602 "An error occurred installing macOS." UserInfo={NSLocalizedRecoverySuggestion=You can try again to complete the installation., NSLocalizedDescription=An error occurred installing macOS., NSUnderlyingError=0x7f9e5dc1c0c0 {Error Domain=BOSErrorDomain Code=110 "The bridgeOS update doesn't satisfy the given minimum version requirement." UserInfo={bridgeVersion=17.16.16610.0.0,0, minimumVersion=18.16.12561.0.0,0, catalogURL=https://swscan.apple.com/content/catalogs/others/index-11-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog, NSLocalizedDescription=The bridgeOS update doesn't satisfy the given minimum version requirement.}}} 2020-11-10 18:12:13-08 theon InstallAssistant[2410]: Stopped operation queue with Error Domain=com.apple.OSInstallerSetup.error Code=602 "An error occurred installing macOS." UserInfo={NSUnderlyingError=0x7f8d04415ca0 {Error Domain=BOSErrorDomain Code=110 "The bridgeOS update doesn't satisfy the given minimum version requirement." UserInfo={bridgeVersion=17.16.16610.0.0,0, minimumVersion=18.16.12561.0.0,0, catalogURL=https://swscan.apple.com/content/catalogs/others/index-11-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog, NSLocalizedDescription=The bridgeOS update doesn't satisfy the given minimum version requirement.}}, NSLocalizedRecoverySuggestion=You can try again to complete the installation., NSLocalizedDescription=An error occurred installing macOS.}

Note that even links to previous betas do this.