How can you say that it would replenish back to that of a bijuu? Seriously, what makes you assume that? It would make more sense to me that it would just replenish to it's original portion left inside Naruto. Also, IMO in terms of plot that just makes no sense that Rikudou would seal portions of the bijuu's power inside Naruto for Naruto to then just immediately go and exhaust it all. On top of that, Rikudou talked to each of them about how Naruto would be their meeting place. Yes it's only opinionated but can't you agree that it seems odd that something as significant as portions of 8 bijuu's chakra being sealed inside Naruto can be rendered meaningless and exhausted directly after being put inside Naruto? Especially when it wasn't even used for it's intended purpose. I have no evidence to give but it would be pretty garbage plot if Naruto didn't still have the bijuu chakra, as the bijuu never even used their 'meeting place'.
Edit: Conversely, there is no evidence that suggests that sealed portions of bijuu chakra DOESN'T replenish so both sides are making assumptions.