You will be able to
purchase the new ATV 4K remote for $59 when it becomes available. It is compatible with the ATV 4K 2nd gen, ATV 4K 1st gen, and the ATV HD.
BTW, it doesn’t have the U1 Chip, so don’t lose it! That is correct, you cannot track it with your iPhone unless you buy an Airtag. Same goes for the new iPad Pros, no U1 Chip, no tracking without an Airtag.