Probable cause under the law is more strict than “the police think”. Even the significantly lower standard of reasonable suspicion is slightly more than “the police think” and yet is not enough to make an arrest.
In my state, if you are driving a car, display signs of alcohol intoxication and refuse to submit to a test, you will be taken into custody, have a blood test administered and driving privileges revoked.
Sure. That is articulable probable cause, namely that you displayed signs X, Y, and Z of alcohol intoxication while driving. That's more than "a cops thinks", but rather that a cop can articulate specific evidence to suggest it's the case.
You can observe and articulate specific evidence to suggest that an individual is infected with COVID-19, or that they were in a situation where exposure makes infection probable.
Great. So make the law that people who have had high probability exposure must self-quarantine and make it an arrestable offense to be both subject to and breaking of a mandatory self-quarantine. I don't mind that being an arrestable offense. I do mind "I don't like the how Spooky23 looks today and they were out in public in a high-risk area, so lock them up!" "I don't like Spooky23 so I'm going to force them to stay in their house or a place of their choosing" has less potential for abuse.
Are we reading the same bill? There does not seem to be a provision to require the government to first advise a suspected carrier to self-quarantine at a location of their choosing and only detain them if/after that requirement is violated.
If that provision exists, could you point it out to me, as I've obviously missed it?