Doesn't look like you've taken the lease, given it's still up... but he's delusional asking for his original 8k deposit. Even 4k is generous, I'd say. He drove it off the lot, he's taking a hit!
That being said... I ordered my MY18 GTS in Nov2017, back when we were messaging about it... took delivery late Feb2018, so it's almost been a year, and I just drove it down to SF. I'd say unless you're getting a deal on a used <1 year vehicle, just buy it new. Part of the fun is neurotically researching every single option, then waiting 3-4 months for delivery, then having to keep the revs down for the first 3-4000kms
Not sure if MY19 will have a GTS trim, seems like the S isn't getting delivered to NA until summer... which would get me anxious on when the MY2020 land.
Regardless... life is short, that guy leasebuster GTS hasn't moved... I'd ping him now that it's a month later and see if he takes $2k.