When I was at the AX Key dinner in 2016, I asked about them making more figures (like Yumemi, Shiori, Kyousuke). Baba said that he is friend's with one of the heads at Goodsmile and said that we should bug them with requests and that he would talk to them. So perhaps he actually did. I think Nagisa was picked because of the popularity of Clannad on steam they decided to go for it.
I hope that they continue and make AIR, Kanon and More Little Busters characters and Yumemi. I fully see a re-release of the Kud Wafter. I just hope other figures get made other than Kud Wafter since she already has a ton of figures.
As for Goodsmile not making figures for Clannad, Goodsmile wasn't really that big in 2004 like Kotobukiya. Wasn't until around 2008-ish where they picked up their game.