What happens to pocket after chin implant removal?

It is very likely your chin is still large from swelling from the trauma of the surgery. It is extremely unlikely your chin will be anything different than what it started like by 6 months afterwards. Please try to be patient and attend your followup appointments with your surgeon. Good luck in your recovery!

Chin Implant removal information/and considerations: For the vast majority of chin implants, removal is straight  forward most commonly using the  same incision that was used to place it. The procedure is often done in the office with local anesthesia with or without some sedation, but also commonly done in the OR under IV sedation or general anesthesia per patient's and surgeon's preference.  Most implants are silicone and are not adherent so slip out readily. Medpor, also called PTFE, may have tissue ingrowth and can be a bit more involved but still can be removed in the same manner.  It is very helpful for your surgeon to  review your prior surgical records to know the size and type of implant used. This may be obtained by contacting your prior surgeon's office or OR facility and request your prior surgical records.
Expectations: if the chin implant was small and removed within the first few years chances are likely that you will return a similar size and shape as before. If the implant was small, the chin soft tissue usually shrinks back down without  sagging.  Often, there is still some gain once the implant is removed due to the scarring and capsule (lining your body makes around the implant) that gives some benefit. On the other hand a large implant placed many years ago, and other factors such as being elderly, having osteoporosis and perhaps smoking that can cause loss of underlying bone due to  bony erosion from the pressure of the implant. In this case  use of a natural filler such your fat or at times a bone graft may recommended for different reasons. Your surgeon may request a  Panorex or lateral cephalometric x-ray to see if this is the case.  Temporary fillers can also be tried such as Jeuvederm, Sculptra, Voluma, Volbella, etc. 
Most important of all make sure you pick a plastic surgeon with great expertise in #chinaugmentation and #chinimplantremoval. 
See the below link on how best to choose your surgeon.

 Hi, I have performed many facial shaping procedures, including Chin Augmentation with dermal fillers or silastic chin implants, for over 30 years.  The "pocket" is a potential space surgically created, within the tissues, to place the chin implant.  This space rapidly closes and should the implant be removed, the space left by the implant removal also rapidly closes.   When the chin is weak, this creates an imbalance making the nose appear larger, the mid face top heavy, the lower face looks short, de-emphasizes the lips and allows early formation of a "double chin".  
 Proper placement of a silastic chin implant adds forward projection to the chin thereby creating harmony and balance to the lower face.  Using the same incision, liposuction can be performed to reduce the fat and further shape the neck.  Excess skin, from below the chin, can also be removed through the same incision.  
 I have found that placement of a silastic chin implant, through a small curved incision under the chin (also allows excess skin removal) to be very safe, quick, highly effective and far less invasive than a sliding genioplasty (requires extensive tissue dissection, bone cuts and placement of metal screws and plates to secure the cut bone segments).  I perform chin implant surgery in 30 minutes or less, often using a local anesthetic alone.  I
Hope this helps.