I think you meant 8620J? You typed 8620C twice.
Anyway, I believe this is highly likely. But I've yet to spot
any perm stix yet on 6606P yet to indicate the swap. So best bet is
to go and see what is the current perm stix on 8620J now.
Cheers.
8620 ytd (23 AUG)spotted on 109 btw this bus should be out of
109 bah
for 6606P not seen it doing on 109 recently
also 
now can see bus like 6767H & 6768E rotating doing on this
svc and 6767H still doing on 109 as of today
today hv 916 959 8617 6767 on 109 while 2612Y spotted on 112
today