The first choice allows you to tap a target creature, which is very useful for tapping down opponent's creatures in order for an easy attack. The second ability to gain first strike and lifelink is also very good, as the Exemplars are a 4/4 creature already. The last ability allows you to exile Exemplars and return it to the battlefield tapped, making it possible to dodge removal like Murderous Cut.
Being a 4/4 creature makes it hard for burn spells to deal with Exemplars, and it has the ability to dodge targeted removal. Its first two abilities are quite aggressive, making this a solid inclusion in current Jeskai builds. This creature is very strong and will see plenty of Standard play, although not as much as its cousins the Mentor and Grand Master. Its existence does allow for Jeskai Wins to become even more aggressive, as if that deck needed another ally.
In other formats, Ojutai Exemplars may see some play, but it's not quite strong enough for Modern and certainly not for Legacy. Commander decks that care about pursuing a Jeskai strategy might find the tapping ability useful, but not for much else. The Exemplars will be strong for their time in Standard, but probably not beyond that.