They might very well be fakes, but that proves nothing, one way or the other. Fake missiles are used to confuse enemy intelligence, for drilling crews in handling the real thing, and for ceremony (on our ship we had fake Terriers we used to exercise the launchers and their crews in rapid reloading activities, so if you tore one up accidentally there would be no unpleasant consequences. And we had a set of beautifully painted "dress" dummies we ran out to impress the locals when we were in port.

The smart intelligence analyst would be taking a close look at the launchers, which are harder to fake,and will show signs of normal wear and tear if they have been used in exercises and drills. They also give us a chance to see what Red Chinese gear looks like (I suspect those launchers were not developed or even built locally, they are probably People's Army surplus.) A fake missile can quickly be prepared for little effort or expense. A proper missile launcher/transporter is a pretty sophisticated and expensive piece of gear,

The very existence of mobile launchers tells you something. You make your weapons mobile to protect them from an enemy first strike. If you plan to shoot first, you don't bother with them.