So assuming that Sirfetch'd evolves from a regular Farfetch'd, that means it will be a Fighting type with access to:
Brave Bird, Leaf Blade, Defog, First Impression, Knock Off, Acrobatics, Roost, U-Turn, Fly, Steel Wing, and Sky Attack
I see it having high attack, decent defenses, and probably low speed, special attack, and HP (someone on Smogon did a calculation and it likely has the same HP as a regular Farfetch'd). But a Fighting type with good attack, that can likely hold the Stick item (considering Alola Marowak still could hold its signature item, I think Sirfetch'd can as well), it should be very fun to use. It also has access to Swords Dance and Agility, so it will be very fun! Hoping it gets some cool moves on its own merit (Close Combat, Sacred Sword, Drain Punch, etc.) And if it keeps Defiant, it will be so much fun since it now is prone to Sticky Web unlike before.
I can't wait to get someone to trade it to me!