The latest (from 20150912) should be the one used in the PDGS right now.
Products generated since 20150912 use this one, but previous data may not have been reprocessed yet.
Sorry I mistyped. Your second link is valid starting 20151209 (according to file name), so 9th of December 2015. So it applies only to products processed after the 9th of December 2015.
I still believe it is not OK…
If you take an example
S2A_OPER_PRD_MSIL1C_PDMC_20151211T121244_R016_V20151211T003541_20151211T003541
(I assume this was processed on 11.12., so after 9.12.) it has references to tiles
55LDB, 55LGB, 55LEB