FWIW, the link also says, "North America market only. Details for the Europe market, please contact: [email protected]."The price isn't the half of it.
This says that anyone who ordered prior to the announcement is eligible.
I don't know about the US, but in the UK anyone who had a P85D reservation in the build queue but who hadn't commenced production was called up by Tesla Inside Sales who told them that they were not eligible for the retrofit, and that the only way to get ludicrous in their car would be to reconfigure it to be a P90DL by paying full price for ludicrous, taking a pack upgrade they might not have wanted, re-pricing the rest of their order to current design studio pricing, and potentially losing access to certain discontinued options as well.
So if you're a UK reservation holder who placed your P85D order in February 2015, but whose car was still not in production by July (which it wouldn't have been due to long RHD production delays), and you chose to reconfigure since you were told that was the only way, then you've had to pay £8300 for ludicrous, £2500 for the bigger pack, reconfiguring to new pricing probably added another £2000 or so given UK price movement earlier in the year, you lost your second charger, your next-gen or executive rear seats, and had to switch from "old blue" to "new blue".
But now it turns out you could have just kept the car you actually ordered and had the fuse retrofit after all.
Is that excrement I see flying towards the air blower?