Gears tactics is set after the E-day, as Rod clarified at e3, and in the interface we can see that two characters should survive(like any xcom like there's permadeath) and the surname of the leader is blurred, we only know that his name is "Gabriel" and the surname will be, according t the source, "Diaz"
Gabriel may be the brother of Oscar, husband of Reina and Kait's dad.
The second connection is the main enemy. Rod talked about a locust mad scientist. That scientist could be a character from the comics, Ukkon, a grey emminence that invented the cyborg parts that allow the control of brumaks, corpsers and so on.
Ukkon is, according to several theories, Niles Samson, the scientist who lead the new hope lab visited in gears 2 and his mind was used as a base for the AI that managed the base.
A few months ago the actor who dubbed samson was in the coalition headquarters, so this may back the theory.