Though China claims to be a neutral actor seeking peace between Russia and Ukraine, Beijing and Moscow signed a "no limits" partnership just before the invasion. The West had only promised sanctions should China provide material aid to the Russian military, which is what it seems these companies have done. This proposal didn't come out of the blue but in response to Beijing's growing vocal and now material support for Moscow.
China has never taken a side in the Russia-Ukraine war, and it's best the EU and its member countries understand that. China has looked at this conflict through an objective lens and offered peaceful solutions through negotiation. Therefore, any sanctions placed on Chinese firms by the EU would be an unprovoked move to which China has the right to defend itself equally.
There's an 8.5% chance that China will get involved in the Russo-Ukrainian conflict by 2024, according to the Metaculus prediction community.