Kadokawa has few stable shareholders and, with the founding family no longer on the management team, the company has lost its identity, so there have been talks of an acquisition for some time.
There was talk of a foreign acquisition of Seven & I Holdings, so they must have been rushing to find a buyer for the domestic company. Recently, Korean financial institutions and funds have been emerging as top shareholders.
I understand the feeling that it would be better to have a company in Japan than to be controlled by foreign capital. Sony is very strong in media, so it might be the best place for KADOKAWA to sell to. There are not many companies that can complete light novels and anime in-house.