Similarly, is shukaku still alive?
In fact, some of those Jinchuuriki were used as Edo Tensei summons from the dead during the Fourth Shinobi World War that concludes the series. But, Shukaku's jinchuuriki is still alive, thanks to Chiyo giving her life to resurrect Gaara.
Furthermore, does Gaara get the one tail back? No Gaara doesn't get his one tail back. After Gaara was kidnapped by the Akatsuki and had the one tail stolen from him the only thing his people cared about was Gaaras well being since he is their leader and everyone respects him and trust him and admire him.
Beside above, did Gaara get shukaku back after the war?
Fans remember Gaara losing his ties to Shukaku during Naruto: Shippuden as he was the first Jinchuriki captured and sacrificed in order to summon the Ten-Tailed Beast. While the series had never confirmed whether or not Shukaku had returned to Gaara after the war, this does give a clue that this is certainly the case.
Why is shukaku small in Boruto?
After Gaara managed to seal Urashiki temporarily, Shukaku reverted to his new small form which fans find adorable. The tea pot was meant to be used as a way to seal Shukaku until Boruto and Shinki could deliver him to the Leaf Village for safe keeping.
