It probably can stay where it is, but keep in mind that when you have the disposer on, it is acting like a pump, and you might end up with crud in the drain for the DW.
The most common problem with a disposer is that its outlet is lower, and you can't make the waste go uphill. It is not uncommon to have to lower the connection in the wall to accommodate the lower height of the disposal. I'd probably just use the DW inlet on the disposal. If you don't have the proper pipe connecting the two sinks, the one with the disposal can push waste up into the other sink...it needs a baffle in that pipe to prevent that and direct the flow down the drain.