In addition to this tweet from Conan O'Brien, I've reached out for confirmation regarding Blu-ray or DVD format ("no comment"), uncut/unedited ("no comment"), and new supplemental features ("no comment").

What I was told, that "everyone is going to be very happy", makes me comfortable placing a heavy bet that it will have been remastered from film source for Blu-ray, as the episodes originally aired (edited down previously for syndication), and with a boatload of extras. This is how WB can kick off their Batman 75th Anniversary Year in style.

Next on my wish list is giving Bill Finger long-overdue co-creator credit on the character and universe.

The reason this has taken so long is a longtime dispute between FOX (who own the show), and Warner Bros (who own the characters and overall license). I heard rumbling last summer that the two sides had finally settled on a split where one side would get toy licensing and the other home video and streaming rights, but San Diego Comic Con (which had Batman '66-branded bags yet again) came and went with no official announcement.

My baseless speculation upon prior rumor is that FOX somehow will benefit from SVOD/streaming rights, having relinquished physical media release and licensed product rights to WB. If FOX has good lawyers, they may still have some sort of interest or stake in the backend of both, but only lawyers and file clerks will ever know for sure.