Can I still get the 2016 15" MBP keyboard replaced by Apple

If you mean the free Apple Keyboard repair program, then that is only valid for up to four years after purchase. I believe the program is expired for a 2016 model since the 2016 model is now considered "Vintage" by Apple.

Since the laptop is "Vintage", official paid repairs may still be possible as long as the part is still available from Apple. However, you may need to have an Apple Authorized Service Provider repair the laptop as long as they do the repairs at their own shop since I don't believe Apple allows for any mail-in repairs for "Vintage" systems which some AASPs will utilize as do some Apple Stores.