Y-30 was never an actual PLA designation, as explained in a episode of Chahuahui(or it might be 将军's video), it was initially just called Y-30 just due to the fact it's design payload is 30t and iirc it at the time had basically the same status as FC-31.
In that case, are there any examples to the contrary (of projects that have had initial official designations changed due to significant rework)?
I cannot think of any myself, including if it is for the aerospace domain that one thinks of specifically.
Now, I personally do expect that the project itself has undergone major revisions which has been a reflection of the rumours in the last half decade -- but whether that is tied to the name or not, is a toss up. There's not enough of a pattern to the madness to establish that as a link.