Typically, you don't want to make a big deal out of coding conventions unless said convention is somehow impeding the project in a significant way. I've seen many a heated argument escalate over things as small as code regions and leading underscores.

That being said, I see no issue with adding == true to a conditional statement. As a matter of fact, I am in the habit of using == false as opposed to a leading exclamation point when testing for negative conditions. I think it's more readable.

If there is an established convention, I say follow it unless there is reason to change. However, it's not really worth raising a big stink about.