Back in the days, switching to a new phone meant you would lose most of your local data. Over time, it became easier to transfer files, settings, and contacts, provided you stay on the same ecosystem. For example, if you get a new Android phone, WhatsApp calls and media will be automatically restored thanks to an online Google Drive backup. However, in case you decide to get an iPhone, there is no official way to recover the calls and media from your Android phone. WhatsApp is reportedly working to fix this warning, thanks to a native solution to automatically transfer your chat history across platforms.
The feature is not available yet, but new leaks indicate that users will be allowed to migrate their chat log from iOS to Android and vice versa. According to the screenshot above, it appears that the process will not be automated and may need to be triggered manually to start the transfer.
It is important to remember that the feature has not yet been implemented, so it may work differently when it is officially released.