See my signature link on why your score dropped at a credit alert. Read the post.
And welcome to the forums!
It's impossible for a name change to drop your credit score.
The alerts you received may have absolutely nothing to do with why your score changed. This is a very common misconception around the forum, but makes sense when you understand how alerts work.
As a thought the name change might have removed positive accounts that were erroneously associated with you. The removal of accounts doesn't trigger an alert by itself I think.