That is probably true...but then, IMHO, it would be an opportunity wasted.
Much better to come with a very decent vessel, like a Type 071 and its escorts, so as to make as good and lasting an impression of both willingness to engage, and strength, as possible.
But we shall see what they do.
Look, this is like being invited to the swankiest party in town
BUT only allowed stay outside the door, with no seat and served just a bag of roasted peanuts and a glass of water with spit in it, while everyone else get full course royal treatment, then what's the point of come dressing in your Sunday's best, eh?
In reality, it's just US want to tell the world "yeah we
did invite China, we showed good faith" while in reality China can only observe, or participate, the least significant portions of the exercise...meanwhile, every other participants can laugh their socks off over the cold treatment China gets at dinner party.
China really don't need to bring anything nice, just adequate for the allotted event and bring more observers and recording equipments. Unless the PLAN plans for a long distance (or round the globe) cruise and made the Pearl Harbour one of their stops, there's really no point to bring major surface combatants along because they'd be idling at Pearl Harbour during the RIMPAC exercise anyway.
So unless China is invited to the more core-level events of RIMPAC 2014, Shichang with Z-8s (in SAR mission package) is more than enough.