I just have seen the “SALE” sign for both devices. WIll be discontinued ?
Which would be a bit unfortunate, as just recently, with newest official LEDE, both device types look very stable to me. No real problems with MT76 Wifi any more.
Because of ample RAM and flash, both devices more “value for money” compared to the AR150.
And better choice for some commercial app, I am just developing.
Only drawback: I would like to see a RTC+battery for the MT300’s, as wireguard VPN is sensitive to correct time, to start up properly.
When you look at the LEDE forum, where I had some long discussion regarding RTC option, you will notice, I am not te only one having the time issue with wireguard. So you might have some competitive edge when offering more RTCs 
MT300N-V2 will not be discontinued.
We will check if the open source wifi driver is working good on this.
For Wireguard and RTC, we will check this closely. I think in MT300N-V2 you can add RTC because it has spare IO. It is just not so easy as AR150 which has a dedicated module.
Would be great, you could change MT300N-V2 pinout also to use the RTC from AR150.
Good suggestions but changing an existing working electronics is a hard decision.