Stylist made my eyebrow too thin while threading and now it looks too weird...will it grow back to normal?

 I'm assuming that you do not have any scarring from the procedure. If you don't have any underlying medical problems, the hair should regrow.. Latisse, minoxidil and PRP can  speed up the process.

This should grow back normally. Prp and progesterone can help regrow eyebrows. See an expert. Best, Dr. Emer

Provided an individual has no underlying abnormality in the eyebrow or underlying issues that would affect hair regrowth, regrowth would be expected within 3-4 months. Aging, thyroid disease, nutritional issues and autoimmune disease can all affect regrowth after a styling mishap.

Yes, it will grow back to normal.  You can use Latisse to speed up the growth process or you may want to consider microblading, a technique in which tiny strokes make a semi-permanent tattoo look like realistic hair.
Best, 
Dr. Fleming