Yes. It is correct.
1/ the first {if $Number} at the top of the whole group controls the usage for posts vs private topics.
[...code...]
2/ the second {if $postrow[post].notifylink} controls the access to the notify code.
[...code...]
2/ the second one gets closed with the {/if}
1/ and finally, the first one gets closed with the other {/if}