I just asked a question which included a question within a pair of asterisks; the word was intended to be read with emphasis, and that is how I would interpret this when reading it. This was almost immediately edited out. Removing the asterisks changes the way you read the sentence (at least to me) but I don't want to roll back before checking if I violated some guidance on title formatting. Is there any guidance or community position on including asterisks, underscores or similar Usenet-style markup conventions in titles, where Markdown is not enabled, to clarify emphasis?
tl;dr: No, there's no rule against it. But, it will probably annoy a lot of users, and that's probably not the effect you were going for.
Markdown syntax does not work in question titles, but people try to use it all the time. Whoever edited your post likely assumed you were trying to use markdown without realizing that it did not work, and was trying to "fix" it for you.
In general, we try to avoid using such markup-looking stuff in titles, mostly for that reason. It looks like a mistake and people will want to fix it.
If you really want to roll back the edit then feel free. We don't have any kind of policy on how to "format" your titles, as long as you don't do anything to actively break the site. But, I would suggest you leave it as-is, as it will distract and possibly annoy the users you're hoping will answer your question. A better option would be to repeat your title, with formatting for emphasis, in the body of your post as well.