https://source.android.com/security/bulletin/2017-07-01#broa...
https://android-developers.googleblog.com/2017/06/2017-andro...
To me, the takeaway from this is that unless you are using a "flagship" device, or one sold directly by Google, you're probably not getting updates in a timely manner.
BlackBerry: PRIV
Fujitsu: F-01J
General Mobile: GM5 Plus d, GM5 Plus, General Mobile 4G Dual,
General Mobile 4G
Gionee A1
Google: Pixel XL, Pixel, Nexus 6P, Nexus 6, Nexus 5X, Nexus 9
LGE: LG G6, V20, Stylo 2 V, GPAD 7.0 LTE
Motorola: Moto Z, Moto Z Droid
Oppo: CPH1613, CPH1605
Samsung: Galaxy S8+, Galaxy S8, Galaxy S7, Galaxy S7 Edge, Galaxy S7 Active, Galaxy S6 Active, Galaxy S5 Dual SIM, Galaxy C9 Pro, Galaxy C7, Galaxy J7, Galaxy On7 Pro, Galaxy J2, Galaxy A8, Galaxy Tab S2 9.7
Sharp: Android One S1, 507SH
Sony: Xperia XA1, Xperia X
Vivo: Vivo 1609, Vivo 1601, Vivo Y55
This list shows the models with a MAJORITY OF DEPLOYED DEVICES running a security update from the last two months.