I have some good news for you: if you have Huawei or Samsung phone, you can install WoT Blitz 8.4 on your Android phone right away.
All you need to do is uninstall the Google Play version and use Galaxy Store on Samsung or AppGallery on Huawei. Both stores have the game updated to 8.4 and you can easily download it.
The donwside is that you will have to redownload all game content again. But that is still better than waiting for Google Play to approve Blitz 8.4, right?