I’ve been watching a few people who I know have been coming and going out of Forge for a little while now, but their matches are not appearing in their Recent Matches list. I would assume that they would at least appear as a “custom” match with a “Forge” gametype. That seems to be corroborated by the fact that there is a “Forge” gametype now, but I’m not seeing the matches.
I’m assuming that the API will hopefully be receiving an update to account for this. Though, I do see that many other things, like the Playlists, Gametypes, and Weapons have been added already.