It's very possible that Finn could be bi...
Though I think this is just one of those things where fans are reading too much into things and just shipping character that have great chemistry. Of no matter what happens people will be mad. If Finn/Poe hook up homophobes will be mad, but if they don't hook up the people who are shipping the couple will complain about Disney not being brave enough for the coupling.
Most people don't use the term "Token" properly. They think it just means a single person of a particular group being included in something. People don't understand that it isn't tokenism unless said person is ONLY there to fill a spot for the sake of diversity.
In fiction a token plays an inconsequential role in the plot, receives little to no character development, and has no motivations outside of the larger group or lead character.
Say what you want about Finn but he's absolutely not a token in The Force Awakens.