Its a TENTATIVE agreement.
DALPA can go back to management and ask for changes any time they want.

Its not a contract until Lee Moak signs it.
Legally, they can re-negotiate right up to the moment he signs it.
Little known fact --> Even if the Delta MEC and pilots ratify it, Moak can refuse to sign it.

Back in 2002 the Mesa pilots at CCAir negotiated and ratified a concessionary contract. Duane Woerth refused to sign it. Said it was way too concessionary. Mesa mangement and the CCAir pilots even sued Woerth and ALPA. ALPA won. CCAir went out of business.

I'd say re-negotiating is highly unlikely in our case though.
The only way we're going to get any changes at this point is by voting it down.