I'm not sure if that is a question or simply a statement of fact.
I can tell you that my Alcatel ONETOUCH Fierce XL, which came with Windows 10 Mobile installed and is a Tmobile branded phone (more or less), got the .164 update, so....
It wouldn't surprise me that ATT 950s also received it.
My phone is not participating in the Insider Program and does not have the "Insider" app installed.