[Inquiry] Please provide clarification on "Link a Device"

The processs of moving an Android account to an iOS device is unclear.

If I have an iOS account, kaitco, and an Android account, octiak, and I'd like to play octiak on an iOS device, using the generated code states that kaitco will be deleted.

Is this by design? Is there no way to keep both accounts going, or is there a way to move accounts back and forth at will through the Link a Device option.