Matt Groening revealed the location of the Springfield which inspired him to name the Simpsons’ town “Springfield.” He’s not saying that the Simpsons characters officially live in Oregon, and even if he did, that wouldn’t retroactively transform the world of the show to have taken place in Oregon this whole time. Groening also based the Simpsons’ names on those of his family, but this doesn’t mean that the Simpsons in any way are the Groenings; just because the Springfield thing is an intentionally vague joke-mystery doesn’t mean that the real-life inspiration for it just ‘becomes’ the in-show truth.
