I wouldn't say it's the GOAT ending, but I did feel it was a great ending.
Do the knowledge on the very first scene, David Chase uses the scene to visually show how he gave birth to Tony (
also, the scene doesn't transition, it's a straight cut to the opening scene, just like the ending is a straight cut)
The female statue: Tony is birth to us, the audience, from between the female statue's legs
Chase foreshadowed, Tony dying throughout the series, here in season 6 (Part A, I believe)
Here is another foreshadowing, when the BK chapter of the mob are eating with Silvio, you actually see the gunshots and the mafioso being shot, and Chase
doesn't implement the sounds of the gun shot until way after (alluding to Bobby's quote of you probably don't hear it coming).
Chase did an excellent job of the show, in that the Mafia aspect of the show was just fish bait to get the audience to watch.
The show was much deeper, and delved into topics of motherhood (
or how not all women necessarily make good mothers) and patricide - the killing of ones father, or father-figure, was heavily implied in the show. First with Tony, nearly killing his Uncle Junior (
a father figure who would play catch with him a child) and then with Tony nearly killing another father figure in Paulie, when Tony nearly killed him on the boat.
Paulie was a gangster that Tony admired as a child and looked up to, Paulie was there to guide Tony when Tony caught his first body.
Patricide was also depicted with Christopher wanting to kill Tony because he thought he slept with Adriana.
EDIT: When the episodes with Tony in a coma as Mike Finnerty first aired I HATED THEM!!!! I thought it was nonsense filler, but way after the fact I re-watched them, went on some great forums, along with YouTube analysis videos, and now I love those episodes.
Those scenes with the Monks slapping the shyt out of Tony for selling them defective heaters (aka leaving people to die, murdering in cold blood back in the real world).
Or while Tony is in a coma he falls down the stairs (
implying they were the stairs to hell) and him seeing the doctor in a coma and the doctor pointing out the black spots in his brain, advising Tony that he caught it early (
meaning his soul can still be redeemed).