I read the article and there isn't anything like "Japan wants to attack China in 2027", the date is the date when they will finish their 5 year armed forces expansion plan.
Aggression on China is implied but as part of USA attack, and as such if it happens, it will happen much earlier since even USA analysts say the China will have military advantage over USA in 2025 (i guess they mean defensive war since Pacific is quite big obstacle).
Most likely all this shit is tied to the same USA pivoting to China which was very recently discussed here about Australia, where US is basically openly threatening Australia into sabotaging their own interest and politics else there will be "consequences".
100% chance that Japanese politicians heard the same thing with carrot dangled being probably the same thing as ever - the resources of Manchuria freely to exploit after US victory (joke on them, US would never keep that promise).