He doesn’t disclose that he’s running for Congress in the article and it seems very convenient to share these opinions as soon as he’s running for office.
Running for Congress is consistent with his stated goal at the end of the article: "No longer can massive tech companies like Google be permitted to operate relatively free from government oversight. As soon as Google executives were asked by Congress about Project Dragonfly and Google’s commitment to free expression and human rights, they assured Congress that the project was exploratory and it was subsequently shut down."
If he ended the article with, "Vote for me! Maine 2020!" It would sound highly self-serving. I believe he simply doesn't see his campaign as relevant to what he's writing here.
This is his retrospective on his time at Google.
He may post other things that combine the two, but this one is clearly focused on the things he experienced while working for one of the largest corporations in the world.
Both need to be evaluated critically.
At this point Sara Gideon is going to win the nomination easily.
It seems to me that if the actions you take are legal, it doesn't matter your size. Who is the government to decide what's too big to operate without their input?
Nowhere in this article do I see evidence of a "change of heart." He didn't suddenly quit to run for office. He fought for what he believed in, putting human rights above profits, until the culture changed so much as to axe him. It sounds like he's taking his wealth and prestige to the place he thinks he will have the most power: senate