Complications from Orbicularis Ligament Release

Recommend seeing before/after photos of your surgeon. Ligament release should not cause eye shape change but transcutaneous blepharoplasty and possibly canthopexy can. Ideal method to address under eye bags and hollowness is transconjunctival lower blepharoplasty with fat bags repositioning so the existing eye bags are repositioned to fill the hollow area (not taking fat from another body part and injecting which is unpredictable due to blood supply issue). See following link and surgical video.

I'm not sure why your surgeon would have even discussed the release of the tendons with you as that is detailed technical information for the surgeon.  We often release the tendons with lower lid bleph, especially when we are repositioning fat.  When adding fat the cannula will also elevate these tendons.  Release of the tendons is not going to change the shape of your eyes.A canthopexy can make an eye more almond shaped.  However when done correctly it should just help to maintain a nice shape to the eye.  

Current techniques in lower lid blepharoplasty often entail release of this ligament to smooth the lower eyelid bags and tear trough depressions.It is quite safe and is an improved technique. It likely will benefit your shape.  Canthopexy is usually with a dissolving suture and is for short term support of your lower eyelid during the healing phase.

The release of the ligament is performed to release soft tissue off the orbital rim.  The canthopexy is more likely to change the shape.