as far as i'm aware, the later strut mount should fit fine. the bolt spacing looks to be the same; the later part just appears to have more material where the shaft is bolted to the mount:
zenki:
http://web.archive.org/web/20190529162000if_/https://www.rockauto.com/info/63/SM5764.jpg
kouki:
http://web.archive.org/web/20190529162005if_/https://www.rockauto.com/info/63/SM5765.jpg
unfortunately, this is only conjecture, as the are not parts physically in front of me. someone with experience on pre- and post-facelift models would need to confirm. it's interesting that the aftermarket have a unique part number for the MY10-12 BM/BR, while the MY13+ shares the part number with the third and fourth gen impreza, and related platforms [GR, GP, VA, SJ, etc.] that have similar rear multilink design.