it's a bit odd that a lender would extinguish an easement ..but they might insist you get it done. In general the grantee of the easement would need to unwrap the grant by a quit claim or some recorded appropriate step .
The language in your deed does not make sense to me but I.m not a lawyer nor in CA..in general an easement must be granted to somebody for something and that language doesn't.t do it in my eye.
If the direct neighbor ties into that line he may have some rights but that is not the scope of your question.
So far there are a lot of holes or unknowns.
DO NOT sign anything w/o some most careful review of your legal options and your bargaining power.
As I posted earlier ...if the builders other options might cost him $200,000 more you have considerable barter position.
I doubt the easement is 5', it's more likely 5 + 5 on each side of the line....check things out with your neighbor!!
Unless you want to wake up to some huge piece of construction equipment ripping up your pad you need to be more active in where this is headed.