I agree that seems likely, but I'm not sure if the choice of the 76mm for the 054A was based on the advantages the 76mm has over the 100mm.
If the 76mm was choosen only because the 100mm didn't fit the space available, then I could imagine that the next frigate might use a 100mm again if the space can be found.
I don't think the PLAN would consider 3 different shell calibers a big logistics problem. If I'm not mistaken they currently need different ammunition for the "old chinese 100mm" guns (053 variants, some of the 051s), the "old chinese 130mm" (the other 051s), the "new 'french' 100mm", the "76mm", the "new chinese 130mm" and perhaps also for the "russian 130mm" (does anyone know if the AK-130 can use the same ammunition as the HP/J-38 ?).