Therefore, this is incorrect: “I wrote a new blog today.” No! A thousand times, no!
And do not say: “Come look at my new blog,” unless you mean the site in general, not a specific post. If you mean a specific post, then say “Come look at my new blog post.”
Saying “I wrote a new blog today” is only correct if you create a new blog, wrote a bunch of posts for it, and then shut it down. To use “wrote” in the past tense implies that the blog is finished and has been shut down, and the word “new” implies that it was just created, so somehow the lifecycle of that entire site/publication/platform got rolled up into one day.
Someone who just wrote an article doesn’t say: “Check out the magazine I wrote today.”
(However, an opinion columnist does say: “Check out the new column I wrote today.” In that case, the group and the singular is the same, which is problematic.)
For the last time: “Post” is a singular noun. “Blog” is a collective noun. You did not “wrote a blog.” You may “write a blog,” meaning you continue to post updates to a specific website, but the only thing you “wrote” in the past tense was a “post.”
(Finally, “pedantic” is an adjective.)