Bee should still be alive. The 8 tails cut off a tentacle, a similar thing we saw earlier in the manga, which we know retains enough chakra to be counted as a tailed beast, as illustrated in the juubi using only a tentacle to power the entirety of the juubi with Obito. We also know that Tailed beasts can be split into multiple places at a time. Bee is definitely still alive, likely having the tentacle that resides within him gain as much chakra as possible and Samehada providing him with any leftover 8tail chakra it had in it. There is no doubt that Bee is living, there are too many possible ways for him to be alive.