The reverse summoning also makes sense, because we've seen that whenever a summon gets too weak it gets reverse summoned back. Also, Susuke didn't expect Manda's consensus when he summoned him- that's why he trapped Manda under a genjutsu and basically used him as both a meat shield and a transporter.
However, a potential plot hole can be argued if you think Manda died during the blast itself, because Manda would have disappeared from the snake register and should have become unsummonable, like
what happened to that one frog Danzo killed.
Also, we don't actually know whether Manda/summons get reverse summoned when they go back rather than just getting sent back some other way, since the summoner would need to be aware that the summoned was weak.
Manda's name was more than likely scratched off the list after his final breath after he cursed sasuke for using him like a bitch. From the looks of it summons have the ability to reverse summon themselves when they want to leave, thinking back to the summon that was killed by Danzou was in the process of reverse summoning himself.
ok but where in the manga states that the summoner can be transported with his summon to the "animal realm" and be resummoned with the said animal if necessary? to me it just seemed that kishimoto pulled that tech out of his ass to save sasuke (yet again) in the first place (just like his amaterasu armor)... no one even knew that sasuke had signed a blood contract with the snakes, or that amaterasu could be used in such a way... he's kishi's golden boy
So Kabuto can ressurect summmons now and make them evolve?