Earlier quoted context omitted.
Vladivostok was recently required to be called 符拉迪沃斯托克 on Chinese maps. China claiming that territory back one way or another does seem to be likely.
You're probably thinking of 海参崴.
In September China released a new map using the old Chinese name (Sea Cucumber Bay) rather than the transliterated Vladivostok.
https://www.spectator.co.uk/article/chinas-standard-map-is-a...