Hi,
It takes some time for the pathology report to come back, so perhaps your father was upstaged from 2 to 3a or 3b. The fatty tissue is removed, along with lymph nodes.
Bladder cancer is a funny beast, some people with stage 3 and/or 3b are actually cured by the surgery itself, but some people aren't, that is why some doctors lean toward chemo as an insurance. Until the last few years it wasn't aggressively advocated unless lymph nodes are involved, but that is changing.
If you want more info about these controversies, you can start here:
blcwebcafe.org/chemocontroversies.asp
In theory chemo should be done early enough to catch any possible escaped cells, but not till a person is well enough to tolerate it. As young as your father is, I would hope he has no other health problems and that surgery went without complications.
Wishing you and your father all the best,
Wendy