Well, you can make wfMessage use whichever language you want. By default it will use the current user language, you can use ```wfMessage()->inContentLanguage()``` to use content language of the current wiki, or you can pass your own language as a param  to ensure it will use the right one, the same as you are here by passing the $msgParams array to wfMsgExt: ```wfMessage()->inLanguage( $language )```. I'm pretty sure it should be in the user language though, as it makes more sense to send emails in the language the user has chosen in their preferences, you can double check that though.