My view on OCT is that it's just another way of using programmable drive strength. The fact that Altera doesn't specify OCT settings for Cyclone IV 3.3V IO-standards doesn't mean that you can't use the programmable drivers to match load impedances in a certain range.
The problem is that Altera seems to discourage you permanently to use 3.3V IO with newer FPGA families at all and doesn't provide more than bare necessities to support it. This is due to the small overvoltage margin which can be easily exceeded when e.g. connecting unterminated transmission lines, and probably also the risk of damaging output transistors by drawing excessive current. So output currents available with 3.3V VCCIO have been cut on purpose since Cyclone III.
If you aren't driving too many IO lines, an additional external series resistor should be considered to adjust the total driver impedance.