You mean like this?
Imperial Guard Codex: Page 31 Telepathic Relay: Whist the Astropath is alive, you add 1 to any of your reserve rolls. In addition, if any of your units arrive using the outflank rule, you can re-roll the dice used to determine which board edge these squads arrives from.
I get what you are saying though and I had not really considered this. "Your reserve rolls" could be seen as only affecting units taken from the IG codex (for the life of me why didn't they update this?!) or any units, provided they are yours, arriving from reserve... Currently as it stands RAW "any" seems (I hate to say it) ambigious... I guess for the purposes of this thread, hopefully GW could update/address this in the IG FAQ in the next round of FAQing.