26th century - the battle of Procyon 5.
Daniels tells Archer directly that the 26th century federation consists of "dozens of species". The statement puts certain limits on the number of member species in the federation - a few hundreds, at most.
Well - the federation contains a few 'dozens of species' (hundreds of species) by the 24th century, as well.
Sounds as if a long period of isolationism - or, at least, limited to non-existent inclusion into the federation of new members - is coming for the federation.
Then again, the 26th-century timeline that we saw, will not happen. The destruction of the Sphere Builders and the Expanse in ENT (the Expanse covered a quarter of the galaxy in that 26th-century scene) prevented that. Whatever form the 'real' 26th century takes in Trek, it will not be like that. The Enterprise
-J might even be different.