Protests about the brutal way the police treat black people are pretty obviously going to make CV19 worse: saying they won't is just implausible.
But on the other hand, saying 'the police can kill people and you are not allowed to protest because CV19' is clearly opening the way for some very nasty behaviour indeed. 'How convenient that there is an epidemic,' the authoritarian thinks, 'now we can say that people are not allowed to protest while we round up people we don't like and ship them off to who-knows-where', for instance.
'Oh,' you say, 'well people are allowed to protest if something sufficiently bad happens, this just wasn't sufficiently bad, especially because it didn't happen to me or people like me'. Well, even that comment isn't straightforwardly racist, which it probably is, I have a quote for you about it.
They came first for the Communists, and I didn't speak up because I wasn't a Communist. Then they came for the Jews, and I didn't speak up because I wasn't a Jew. Then they came for the trade unionists, and I didn't speak up because I wasn't a trade unionist. Then they came for the Catholics, and I didn't speak up because I was a Protestant. Then they came for me, and by that time no one was left to speak up.
I'd suggest instead that if it's desirable that people not protest then a way to achieve that, if you are the police, is probably not to kneel on their necks for 9 minutes while they beg for their life, until they're dead. I mean, I don't know, but that seems like a good start, don't you think?