This is the same argument as justifying the NSA's mass surveillance with terrorism. Because lives are involved, it's propagated like a killer argument. Fact is, you don't know if even worse things aren't going to be enabled with this technology.
An important part of the NSA problem is that terrorist conspiracies are a largely imaginary boogeyman. The vast majority of its collection is unwarranted. But the pandemic is real, we know that the damage it does is directly related to the effectiveness of contact tracing, and we know that anyone having contacts outside the household is doing an unusual and extremely dangerous thing.
This is more like tailing people who buy bombs and visit crowded public places with them.
You are not only surveilling those that do "unusual and extremely dangerous things" as in they get within a few meters of other people, you are surveilling everyone. This is not just tailing people who buy bombs.
This technology is designed in the open in a privacy sensitive manner. Your phone tells far more to your cell phone provider, Apple/Google, all the apps providers you have, and credit card companies than this technology ever will.
Cell location is already available to criminal investigation by law enforcement agency under warrant. It's a simple matter of legislating to make it available to epidemic investigation by health agency under warrant-like procedure. South Korea made such law after 2015 MERS epidemic. It does not enable NSA-like mass surveillance. Just do it now, so you can use it the next time.
