The resolution 3440 x 1440 is really nice for WoW and the hardware should handle it. As for FPS - even super modern setup won’t give you ~144 FPS in BfA/current-expansion zones. It still should should run fine though.
You should ask that question before you buy new hardware/equipment
But the answer is no.
Even an AMD Ryzen 3900x or a Intel 9700K won’t come close to stable 144 FPS in WoW.
You can reach those peaks while questing with lowered settings, yes, but in general you are CPU bound when more stuff is happening like many players/NPCs acting at once (raids, cities, bgs, even 5man dungeons).
34" you will have to sit like 2 meters away to even see anything. CPU is weak for nowaday standards. If your pc doesnt have issues now, maybe it will handle it somehow. I wouldnt expect a miracles here.