33 years old - Can a chin fat transfer be reversed?

Depending on why you are not satisfied with the treatment you received, it may be prudent to wait (if it still seems swollen or potentially too big) as it can take more take then expected for swelling to full resolve.
It is hard to reverse fat transfer, as it is permanent. Depending on where the fat was injected, it may be able to be directly excised, or you could even consider Kybella-- but the caveat is there is always risk with any procedure, and kybella could dissolve more fat than you intended, or cause damage to nerves in the vicinity that move the muscle around your mouth, leading to asymmetry. An Ultrasound done by your provider could be helpful as well.
I would speak with your surgeon about this.

Fat transfer is not a good option for chin augmentation.
Removing previously grafted fat can be challenging. The provider who did your procedure is responsible for the outcome and that is probably the right person to talk to about removing the fat or revising your outcome.
Some areas can be treated with Liposuction but Liposuction will not differentiate grafted fat versus native subcutaneous fat.
Most people don’t have that much fat in their chin region anyway so doing liposuction there may or may not be effective at removing any fat.
I suppose it depends on where it was grafted and on each individual person.
Regardless your surgeon is the one who did the procedure and that is who is responsible for the outcome.
If you want a proper second opinion consultation then schedule those as an in person consultation. For a second opinion consultations patient should come prepared with copies of all the before and after pictures and ideally a copy of your previous operative report.
Best,
Mats Hagstrom MD