ASM 12c compatibility
You can use 12c ASM for 11g databases (even 10g), neither the MOS note nor the forum thread says you can not use it.

As far as the table in the MOS is concerned, for 12c, just ignore the first column. Starting with 11.2, the clusterware and ASM come together integrated, called Grid Infrastructure, and not separately as in earlier releases, so they will always be the at the same version. The table clearly shows that 10.2 - 12.1 databases are all certified with 12.1 ASM.