How to update WhatsApp after migration
Once you got back all your iPhone messages and media we suggest to update to latest WhatsApp from Google Play Store!
Before updating, just as a precaution, perform a LOCAL WhatsApp backup, as shown in the tutorial below. Please note: Google Drive backup will be available once you update to latest version.
Now you can safely uninstall the old version and install the new one from Google Play Store . You'll be asked to activate WhatsApp again, this is expected and not an issue (you'll not loose the imported messages).