About 5.1 update for M4 Aqua

After seeing Xperia C4,Xperia C5 Ultra and now Xperia M5 got android 5.1 update out of the nowhere should we expect it on M4 soon?
Those phones should skip 5.1 and go directly ti 6.0 but Sony changed their minds...
Only M4 left on 5.0 for now...

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