Unfortunately for your point, the Gospel of Thomas was specifically excluded from the canon back when it was being defined in the 300s -- as were a number of other "gospels".
It's a happy accident that a copy was rediscovered -- but the reason it was lost in the first place, was that it carried no Scriptural weight: nobody wanted or needed a copy.
Mostly, it wasn't needed because it doesn't say anything particularly different from the canonical Gospels. The only difference that stands out in my mind is one little passage where Jesus takes Thomas aside and tells him a secret that he's not supposed to reveal. This is probably a later addition of the Gnostic sects.
All that to say: there are reasons that the Gospel of Thomas isn't in the canon, which do not require the introduction of dark, modern-day Fundamentalist conspiracies.