My blog was removed on June 12th but my blog returned on June 14th.
I believe that was when I first noticed the disappearing comments problem. Everyone else's comments on that post remained intact but my own comment had disappeared.
So this is a definitely a problem that started after the removal and restoration of my blog.
If this tale is real, we see what appears to be another effort in the war against spam, with a twist.
- The blog owner posts comments, in her / his blog, and in other blogs where he / she is known and unknown.
- Her / his blog is spuriously classified as spam, and both the blog, and the owning account are removed from Blogger.
- Comments previously posted are removed, possibly by the Blogger spam removal bot.
- The blog owner has the blog reviewed, and the Blogger account and blog are restored.
- Comments previously removed are not restored, and additional comments posted later are also removed.
So, in spite of my previous analysis of Blogger and spam comments, Blogger may be doing something about spam comments.
If your blog was recently deleted for spamming, then later restored (possibly after you completed the 4 step spam review), and you think (though probably do not believe) that your comments, posted in various Blogger blogs, are disappearing, maybe you are not imagining what you are seeing.