Jin's lack of professionalism is legendary, and this totally makes the agency lose face.
Kitagawa can punish him all he wants for Jin's lack professionalism for all I care. He deserves it.
But I don't think there will be any harsh punishments like suspending works though since marrying isn't a crime, not like underage smoking or drinking. Meisa's probably the one having it harder on work than Jin since she is (probably) pregnant.
Anyone know what happened at Kimura's time? There was a press conference and he announced it at a concert after a fax, right?
We really can't compare this with Kimura's situation. Kimura and Shizuka had dated for months and he did inform the agency before he got married. He held a press conference by himself without help from the agency and he announced it at a concert first after the tabloid published the rumor about the pregnancy but before the agency sent the fax.
Another difference is Kimura's status and Jin's status. Kimura was and still is the biggest star the agency ever managed, he had tons of CMs, successful dramas and movies and he has SMAP, the biggest act of the agency at the time. Jin doesn't have any of that. It would be harder and stupid for Johnny to punish Kimura by pulling off planned projects or not giving him the new ones. But it won't be that costly for Johnny to shelf Jin after his current deals are done. If Japonicana flops or 47 Ronin only has a moderate success in Japan, he probably will just let Jin disappear.