When can the support be expected

Your best bet is to just use 802.11ac cards with your Mikrotik, however Mikrotik is showing no interest in supporting this. You can get more throughput on same channel sizes, and even use up to 80mhz width with 750/750 air rates, and up to over 500+mb true throughput!

UBNT is already on this and testing units out, looks like they're taking the lead in wireless and leaving Mikrotik in the dust! Sucks because I'd love to see 1ms pings on 802.11ac and 500+ throughput with Nstreme!

i don't believe Mikrotik is just leaving this out...

and if we have products like Sextant we cannot even change the wireless cards... so the best bet would be to wait for Mikrotik to work out something on supporting this.

i think showing faith in a product and its developers definitely pays back.