Can I know why the extracted area with a Dental Implant and bone graft wouldn’t be stitched?

I was explained the procedure and would like to know if it sounds right. A missing tooth area will get a bone graft and implant placed and stitched up. The neighboring tooth would be extracted, bone graft and implant placed and it wouldn’t be stitched. Can I know why the extracted area with an implant and bone graft wouldn’t be stitched? Just worried that it would get infected, inspite being on antibiotics. Thank you.