If an organization conducts counter-reconnassaissance it does not, in my opinion, suddenly become Infantry. If it starts clearing trenches and buildings and digging-in it might be entering the realm of Infantry, but the destruction/neutralization of enemy recce to me is a Cavalry task.
In the heavy metal setting, I agree that if an OP engages enemy recce its ability to detect further forces is compromised. If the unit or sub-unit screening a higher level unit has some combat power beyond the vehicles in the OPs, however, then it can destroy recce without necessarily compromising the OPs. That combat power does not have to be tanks or mech infantry. It could simply be other recce vehs with firepower that are not in OPs themselves.
In Canada we tend to assume this whole piece away. I have been in JCATS and FTXs where there are zero plans to deal with enemy recon assets. The screen lets them through and they reach the main body. In offensive operations, our advancing main body is left to deal with enemy OPs. Down south we were taught (based on NTC) that he who wins the reconnaissance fight wins the whole fight. We can ad-hoc it, or we can build it by design.
Turning to the contemporary operating environment, I admit that the counter-recce piece becomes more fuzzy (along with everything else). Counter-recce, however, can involve more than just "kinetic" options (EW/CI etc etc). Looking at the kid with a cellphone scenario, I venture that one organization could handle both the surveillance of the target and the protection of the "Act" forces from early detection.
Without changing our terms (recce, cavalry etc) we can examine ways to builld new capabilities into our organizations. A Recce Sqn can be given assets (permanently or otherwise) to achieve counter-reconnaissance roles.