Summary
After you install this update for Microsoft Skype for Business Server 2019, all the key creation and references for MSExchangeOWA are moved from "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchange OWA" to the new location "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ExchangeServer\v15\MSExchange OWA”.
How to get this update
To get this update, install the December 2019 cumulative update 7.0.2046.151 for Skype for Business Server 2019, Conferencing Server.