Tampines North would make sense but that is only in 2019 that
the first set of flats in Tampines North will be ready. It if it
not ave 9, it will be ave 5. But since there is 118/46 recently
launched in ave 5, I think the map indicates ave 9 here and
tampines concourse.
The map has been taken down, but from what I remember it's
something like this:

Ave 9 is indicated by the black box.
So 68 does use a small part of Ave 9, but not the entire stretch
like 27. Of course it's always possible that 68 will only be
introduced as Ave 10 - Ave 9 direct, and will only be amended into
Tampines North in 2019.