STATISTICS_NORECOMPUTE in Rebuild Index

It specifies whether distribution statistics are recomputed. The default is OFF.

ON

Out-of-date statistics are not automatically recomputed.

OFF

Automatic statistics updating are enabled.

Indeed, statistics are recomputed during the index rebuild.

Dont think that it stops SQL Server from updating the statistics at the time of a rebuild; that is NOT what it does. 
Statistics are ALWAYS updated at the time of a REBUILD; this cannot be turned off (nor would you want to).

Instead, STATISTICS_NORECOMPUTE stops the database-wide auto-updating from updating the specific statistics for an index (or column-level statistic) that was created (or rebuilt) with this option turned on.

STATISTICS_NORECOMPUTE – When would anyone want to use it?

HTH

STATISTICS_NORECOMPUTE

During Index Rebuild, one of the parameters a user can set is Statistics_NoRecompute.
The default value is OFF which means "Automatic statistics updating are enabled"
ON = Out-of-date statistics are not automatically recomputed