Not quite, although when it finishes I think it says something like "All tables updated". It actually only updates stats for tables where at least one row has changed.
If you do UPDATE STATISTICS, and you do it on ALL tables, even ones for which no changes have been made, then (contrary to "I read that sp_updatestats is never recommended") I reckon that sp_updatestats would be better 
Better still, IMHO, would be to interrogates the meta data to see how many rows have changed (either as a percentage of the total rows in the table, or according to some per-table settings that you have defined) and then Update Stats only one ones that need it.
Depends how big your database is, how long UPDATE STATS currently takes to run, and whether you have a 24/7 system where you have no, or only a small, housekeeping window.
On a small database with no other concerns just updating the lot, every night, means that users have tables with STATS in best-possible-condition. Unless the database is READ ONLY 