No, not "the next byte". After the chip have evaluated the address byte, it will remember the result of that evaluation until the next time it receives a 9-bit transfer with the high bit set.

So you may use any 8-bit protocol in between the address-byte transfers.

You may have one byte address and one byte data. Or one byte address and 10 MB of data.

Did you try google and open the link I mentioned? It did help with the explanation. There are a number of references to be found that spends pages explaining this mode. Both for chips that have automatic address processing, and for situations where the user have a PC-class UART without a 9-bit mode where they use the parity support just to get a ninth bit when sending and receiving (but then obviously having to play with odd/even parity etc).

The link I mentioned did tell how the receivers have an address and how you could mask bits to handle broadcasts where you may send to either a specific receiver or to all connected receivers.

The reason I could not post a direkt link is that Google creates a temporary link when I do the search - possible since they have a huge number of books digitized and available in their own databases. But it is reasonable that if you do a search with the same keywords, you should also see almost the same search matches.