From a pragmatist point of view, to say that what is rational for us now to believe may not be true, is simply to say that somebody may come up with a better idea. It is to say there is always room for improved belief, since new evidence, or new hypotheses, or a whole new vocabulary, may come along.
For pragmatists, the desire for objectivity is not the desire to escape the limitations of one’s community, but simply the desire for as much intersubjective agreement as possible, the desire to extend the reference of “us” as far as we can.
Insofar as pragmatists make a distinction between knowledge and opinion, it is simply the distinction between topics on which such agreement is relatively easy to get and topics on which agreement is relatively hard to get.