I would not be surprised the adverse impact of the lack of a tail emission in a Cryptonote coin will manifest itself in Bytecoin before Monero reaches its tail emission. The premine/ninjamine in Bytecoin will provide some very useful data here.

Edit: The onset of the tail emission in Monero would also be delayed due to fluctuation in the Monero blocksize. This is due to the impact of the Cryptnote penalty function on the emission when the blocksize grows.