I don't think there's an open talkback line from the network master control counting down the times to a SR. However networks have made their productions control room audio feed available on election night so the local stations can listen in and know what's going to happen.
I believe Fox can remotely control and override a stations signal for a special report.
: Worth noting that some special reports are optional while others are mandatory.
That's a major difference to the UK.
The BBC have a permanent talkback circuit to every English region and the three national presentation operations (Wales, Northern Ireland and Scotland). This usually is a switched talkback from Network control for each network (NC1 or NC2 usually) but NC1 is switched to talkback from the news gallery for the integrated headlines in the One/Six/Ten o'clock News. (This feed had the director and the digital countdown voice on it.) This is a complicated network switch - as the ident before the One/Six/Ten is an opt-controlled by NC1, the 15" headline opt in the headline sequence is an opt controlled by the One/Six/Ten gallery. Only a brief period to make the talkback switch every day. (I think NC1 switch it)
For the General election, Children In Need etc. and other shows with major opt-outs controlled by a particular production gallery, the talkback will be switch to those.