I think that Google removed it from their results intentionally. Google has the ability to restrict results, and for it to be weighted so highly after they "fixed" it, and because they gave no indication of what was wrong, I think the "fix" was to remove it from the blacklist.
However, it doesn't change that I use Gmail and will continue to use it. It's still the better product for the money (free).
The removal and fix need not have been so blatant - a breaking change for some sites might have been prioritized, and the fix to that break may have had other work pushed ahead of it. There doesn't need to be an explicit blocklist or clearlist in play to make some customers more important.
Google products have one connecting line in them. They make it easy to adopt and are used to collect data. Whether it is user data or users helping in training a system (captcha, Google voice, ...)
However, it doesn't change that I use Gmail and will continue to use it. It's still the better product for the money (free).