Two weeks into the writers room and, without The Always Sunny Podcast, we haven't heard much at all as to what they're chattering on about in there (aside from dick jokes, apparently), but one thing does now seem clear: Megan Ganz is not writing, if involved at all, on Season 17.
When Rob McElhenney first shared a photo of the writers room on social media, the Glenn Howerton portrait in hand seemed to indicate not everyone was present, however with some new information that seems to be strictly pertinent to Glenn.
It's a smaller writers room this year, per Dave & John Chernin on the "We Might Be Drunk" Podcast. They stated there are two women out of the seven writers for 17 (plus Rob, Charlie, and Glenn), which confirms that the photo Rob shared encompasses the full team:
The WGA site is generally pretty reputable, as only members of the Guild can edit it, but the deletion should still be taken with a grain of salt. There is a small possibility this was a mistake and credits can be updated at any moment, all the way until scripts are finalized (which won't be for months); considering how many projects these guys always have overlapping, anyone might be brought on later.