Okay, first of all I believe the specs ONI posted for YJ-18 are inaccurate. They seem to have simply taken the specs of the export version of 3M-54E, and have believed rumours that YJ-18 is a straight up copy of 3M-54E. The few pictures we have of YJ-18 do not depict a missile geometry anything like 3M-54 I wrote that here:
https://www.sinodefenceforum.com/plan-anti-ship-missiles.t6345/page-8#post-335707
As for the overall flight profile, again, the 3M-54 has been in service for a long time, and has been bought by many countries. YJ-18 is meant to have a similar flight profile to 3M-54 (which is probably where the misunderstanding of YJ-18 being a direct copy of 3M-54E came from), with a subsonic cruise phase and a supersonic terminal phase.
The way it works is that the missile is basically "two stage" with a folding wing and outer first stage/shell in operation during the subsonic phase, with the inner second stage/core which fires up its engine for the supersonic phase after the first stage is detached. A CGI video of the method is here:
Such a missile is not actually that much bigger than a standard cruise missile because the subsonic first stage is a relatively thin outer casing. The booster to propel the missile from the VLS of course is no bigger than a normal booster for a normal cruise missile.
Also, keep in mind that 3M-54E is the export version of the missile with a shorter range (220km) for MTCR compliance. The 3M-54 for domestic russian use has a range listed from 440-660km. Both the export and domestic versions are the same size; 8.22m with a diameter of 0.533m
The longest version of the Chinese common VLS has is 9m long with a diameter of 0.85m. From pictures and video (see my first link, and google YJ-18 launch video) we know the YJ-18 is hot launched via CCL style, meaning its overall diameter is definitely a bit smaller than 0.85m although we don't know the length of YJ-18. If anything YJ-18 seems to have a greater width to length ratio compared to 3M-54, although whether that's because YJ-18 has similar length to 3M-54 and is much wider (i.e.: a bigger missile), or is a similar width to 3M-54 but much shorter (i.e.: a smaller missile) is one we can't confidently tell yet. If I had to bet I'd say the former, given the rough diameter of YJ-18 in the launch video (it's on youtube if you want to watch it) seems only mildly smaller than the estimated width of the VLS 0.85m wide cell. (edit: actually on second look it appears to be about 2/3 the width of the lid, so assuming the lid is 0.85m wide, then a minimum estimate puts YJ-18 at a 0.57 diameter, meaning it's probably a little shorter than 3M-54)
So to answer your question, not only is such a missile perfectly plausible and able to fit in the PLAN's VLS, but the range numbers listed by ONI are probably smaller than what YJ-18 actually is capable of given they're incorrectly assuming it's a copy of export 3M-54E.
