They will still need to “wait” for the new President to sign off on any package. This is just an initial OK.
Unless we are talking of an emergency transfer, which doesn’t make sense the KC-46 is a brand-new system yet to be exported, it will take Israel at least 1-2 years to PREPARE to receive the new tankers. Might as well start early.
“KC-46 is a brand-new system yet to be exported”
And still at least a year away from delivery to its primary user, the USAF, iirc