Is this old filler? (Photo)

The change in your chin's appearance could be due to a number of factors, including the facial lift, the filler, or natural changes due to aging.
A facelift can alter the shape of your chin indirectly by changing the tension and distribution of the skin and soft tissues in the lower face. However, this would typically result in a more defined, not necessarily pointy, chin.
As for the filler, while it's true that some types of fillers can last several years and there have been reports of filler migration, it's less common for fillers to migrate to a degree that would significantly alter the shape of your chin.
However, without a physical examination and perhaps some imaging studies, it's difficult to determine the exact cause of the changes you've noticed. I would recommend discussing your concerns with your plastic surgeon or a board-certified dermatologist who has experience with dermal fillers. They can evaluate your chin and possibly use ultrasound or other imaging to see if any filler remains.
If migrated filler is found to be the cause, there are enzymes like hyaluronidase that can be used to dissolve hyaluronic acid-based fillers. If the change is due to the facelift or natural aging, other treatments or procedures might be considered to restore your preferred appearance.
It's important to communicate your concerns and your aesthetic goals clearly with your doctor so they can provide the best advice for your specific situation.

Most fillers would have metabolized after three years depending on the filler used. It would be unusual for it to migrate after such a long time if it is filler. That being said, an exam may help you determine if any remains. If so and HA filler was used, it can be dissolved using hyaluronidase.